SOPOT, Bulgaria -- Shortly after sunset on March 21, 2015, the skies above Bulgaria's biggest, and last remaining state-owned, armaments factory filled with the crackle and fury normally associated with a battlefield.
The massive fire at the VMZ plant destroyed a large cache of weapons and ammunition and terrified residents of Sopot, central Bulgaria, and neighboring towns abutting the Balkan Mountains that stretch from Bulgaria's western border with Serbia to the Black Sea coast.
Emil Kabaivanov, the mayor of nearby Karlovo, described fire plumes up to 200 meters high: "You could see things exploding in the air."
Less than a month later, on April 14, there were more blasts and more damage at VMZ.
Two weeks after that, a major Bulgarian arms dealer, Emilian Gebrev, fell into a coma, the victim of a poisoning that he alleges some state investigators still attribute to a bad salad and "other ridiculous claims."
All three incidents were part of a string of unexplained explosions (and a poisoning) affecting Bulgaria's arms industry, beginning more than a decade ago and seemingly intensifying after Russia invaded and occupied Crimea in 2014 in the first phase of its expanding war to subdue Ukraine.
WATCH: A special RFE/RL investigation looks into allegations of Russian sabotage, cover-ups by Bulgarian authorities, and whether Bulgarian arms depots are still at risk as Russia's war in Ukraine enters a second year.
"Whether it's Russian involvement or someone else, I can't say," said Sopot's former mayor, Veselin Lichev. "But in your mind, it’s absolutely possible."
Since 2014, the incidents -- some of which resulted in fatalities -- have coincided with Bulgaria's provision, alongside NATO allies, of munitions and other military equipment to Ukraine that has dramatically increased with Russia's full-scale invasion of Ukraine a year ago.
Subsequent reports suggest VMZ was storing munitions to be sent to Ukraine through intermediaries such as Poland and the Czech Republic.
Bulgaria's record of stalled or seemingly ham-fisted investigations has fed suspicions that authorities are reluctant to fully probe suspected Russian involvement.
In some cases, damning evidence has emerged of Russian sabotage, and outside disclosures have forced Bulgarian officials' hand, prompting critics to suggest a dangerous pattern of cover-ups that could compromise domestic and Western security efforts just when Europe needs them most.
"I am very worried," Martin Dimitrov, a former lawmaker with the pro-European Democratic Bulgaria alliance, told RFE/RL's Bulgarian Service recently, calling it "a matter of national security."
"If we are letting people come into Bulgaria who commit sabotage and afterward don't face any consequences from the state," he said, "this sabotage will continue as long as there are no countermeasures, as long as we don't defend ourselves."
Arms For Ukraine And A Mysterious Poisoning
Dimitrov and former Defense Minister Velizar Shalamanov have called for a special parliamentary committee to oversee probes by the Prosecutor-General's Office into the blasts and investigate alleged cover-ups by Bulgaria's security services.
"If we are vulnerable because there are people who haven't proven their integrity, that have a certain weakness that makes them favor foreign interests instead of Bulgarian interests, that means that we can expect these kinds of provocations again in the future," Dimitrov said.
Critics such as Dimitrov say Bulgarian investigators have done little to try to find those responsible for the blasts and other attacks. Arms dealer Gebrev fell into a coma on April 28, 2015, after an unidentified phosphorus-organic substance was placed on the door handle of his car by a Russian agent, prosecutors would ultimately conclude.
But for more than three years, investigators made little headway and blamed Gebrev's near fatal illness on an arugula salad contaminated with pesticide.
It was only after British investigators linked the Gebrev episode to a suspect in the 2018 Novichok poison attack in Salisbury, England -- allegedly carried out by agents from Russia's GRU military intelligence -- that Bulgarian prosecutors had to publicly acknowledge he was probably the target of something more sinister.
In 2020, Bulgarian authorities charged three Russian nationals in absentia in connection with the attempted assassination of Gebrev: Denis Sergeyev (aka Sergei Fedotov), Yegor Gordiyenko (aka Georgy Gorshkov), and Sergei Lyutenko (aka Sergei Pavlov).
British police say they have evidence of Sergeyev's involvement in the 2018 poisoning of defected Russian spy Sergei Skripal in Salisbury allegedly carried out by GRU military intelligence operatives Anatoly Chepiga and Aleksandr Mishkin.
"They were just forced by outside pressure, outside factors, to start this [investigation] with extreme reluctance," Gebrev said.
WATCH: An analyst at investigative journalism outlet Bellingcat says gait-recognition technology could identify an alleged hit man caught on film in Bulgaria in 2015.
In July 2022, following Russian President Vladimir Putin’s full-scale invasion of Ukraine months earlier, an ammunition depot belonging to one of Gebrev's companies, EMCO, went up in flames in the city of Karnobat, in eastern Bulgaria.
Gebrev said publicly that he was "100 percent sure" Russian operatives were behind the Karnobat fire, though he later acknowledged to RFE/RL that he had no direct evidence to confirm this. It is also still unclear whether any of the munitions in Karnobat were destined for Ukraine.
Former Bulgarian Prime Minister Kiril Petkov has estimated Bulgaria provided around one-third of the ammunition for Ukrainian defense forces in the early stages of Russia's invasion, which began on February 24, 2022.
Gebrev speaks defiantly of the Bulgarian arms industry, which is a major manufacturer of ammunition for the kind of Soviet-era weapons that are widely used by the Ukrainian military.
"The Bulgarian [arms] industry in past years and again now, with this mindless war going on, has proven how important it is," Gebrev said. "How many countries from the former Soviet Union and Warsaw Pact can pride themselves on preserving such an industry? They are very few."
Then and now, he has alleged a cover-up by Bulgarian authorities.
"Even now, there are people who work for the security service DANS (the State Agency for National Security) that, to this day, claim there was no poisoning, there was no terrorist act, that nothing happened," Gebrev said. "Even the chief prosecutor started talking about the arugula and other ridiculous claims."
Forced Hand
Nearly all of the fires and blasts at ammunition depots have gone unsolved or been chalked up by Bulgarian officials as accidents. But six years after the VMZ explosions, many of those same officials were forced to rethink those incidents.
After the British disclosures and a Bellingcat open-source investigation identified the Russian GRU team linked to the Salisbury poisonings in the United Kingdom, the Czech government in 2021 accused Russia of "state terrorism" over a deadly explosion at an ammunition depot in Vrbetice, Czech Republic, in 2014.
The two alleged GRU agents implicated by Czech authorities in the Vrbetice blast -- Aleksandr Mishkin and Anatoly Chepiga -- are the same accused by Britain in the Skripal poisoning together with Fedotov, whom Bulgaria has charged in Gebrev's poisoning.
Some of the munitions that were destroyed in Vrbetice belonged to Gebrev and were reportedly of a caliber that suggested they were destined for use by Ukrainians rather than Czechs, although Gebrev denied they were intended for reexport.
Travel records and other documents placed members of the purported GRU team in Bulgaria, too. The disclosures forced Bulgarian authorities to reopen their cases into Gebrev's poisoning and the VMZ fires.
The Prosecutor-General's Office announced within days that it was investigating six suspected Russian agents who were in Bulgaria around the time of Gebrev's poisoning, the VMZ incidents, and explosions at two other Bulgarian arms depots, one of which was storing arms for Gebrev near the village of Lovnidol in north-central Bulgaria.
A spokeswoman, Siyka Mileva, said a "significant amount of ammunition and explosives" destroyed in the November 2011 incident in Lovnidol was "intended for export to the Ministry of Defense in Georgia."
Mileva added that "the purpose of the actions of the Russian citizens was to prevent the deliveries of special production" for Ukraine and Georgia, where Russia has a major military presence in two breakaway regions -- Abkhazia and South Ossetia --it recognized as independent countries after Moscow and Tbilisi fought a five-day war in 2008.
Russian officials have denied any involvement in the Bulgarian and Czech incidents.
At the April 2021 press conference, the Bulgarian prosecutors also announced that physical evidence concerning the VMZ blasts had been destroyed in a fire at an Interior Ministry building in 2015.
Initial news reports suggested that a possible short circuit had triggered the fire at the building, previously known as the Institute for Special Technology. But at the press conference, prosecutors suggested it had been deliberately set.
The forensics report on the fire concluded it "did not occur as a result of spontaneous combustion," prosecutors said.
In the days before the May 31, 2015, fire that destroyed the evidence, two alleged GRU agents later charged in Gebrev’s poisoning had left Bulgaria, according to details from travel records published by open-source sleuths at Bellingcat.
The two alleged agents -- Gordiyenko (aka Gorshkov) and Sergeyev (aka Fedotov) -- crossed into Serbia from Bulgaria on May 29, 2015, and flew to Moscow from Belgrade on the same day, Bellingcat reported, several months before a possible link between the Sofia fire and Russian sabotage was made public by prosecutors.
Since the press conference, the Bulgarian Prosecutor-General's Office has not issued any public statements about the investigation.
'They Don't Want The Truth To Come Out'
One unsolved incident of explosions destroying a Bulgarian arms depot that prosecutors have not linked to possible Russian sabotage occurred more than a decade ago near the eastern Bulgarian town of Straldzha.
Mitko Karakolev is still haunted by what happened at the Straldzha facility owned by the Bulgarian arms company Bereta Trading on June 5, 2012.
Three people were killed, including Karakolev's former colleague whom he'd known since childhood, after fire and explosions tore through the arms depot.
"No matter how many times I go around the facility, I won't be able to pull my friend from the rubble where we found him in pieces," Karakolev, who worked at the facility, told RFE/RL’s Bulgarian Service.
The force of the explosions were so powerful that many locals mistook them for an earthquake. More than 600 people in nearby villages were evacuated.
Atanas Balakchiev, who was at a nearby cottage retreat called Lilac Hut, says he will never forget what he saw.
"I honestly thought it was a nuclear war. I went out in front of the hut and turned in that direction and I saw something like a mushroom cloud after an atomic bomb. It was going up and up," Balakchiev said.
The initial investigation said the disaster was sparked by workers who were disassembling a Dvina rocket warhead. The owner of Bereta Trading, Desislav Delev, was charged with negligence but acquitted in an initial trial.
Prosecutors filed new charges, but more than 10 years after the deadly incident, there's still been no final verdict.
Delev accuses prosecutors of failing to investigate the possibility of Russian sabotage. On the day of the explosions, a repair crew visited the facility to fix a broken security camera, he says.
"They just don't want the truth to come out. They need someone to blame. It doesn't really matter if he's guilty or not," Delev said.
A forensic report on the Straldzha incident obtained by RFE/RL’s Bulgarian Service shows that the facility was storing weapons on behalf of the Bulgarian company Sage Consultants, which the Russian government blacklisted last year.
Delev says the arms his company was storing on Sage’s behalf were destined for Georgia, a claim backed up by copies of permits published by the Bulgarian investigative outlet BIRD showing that Sage, which did not respond to RFE/RL's request for comment, was authorized to export weapons to the South Caucasus nation. One of the permits was issued two months before the blasts that tore through Delev’s facility.
"The fact that they put the company on this blacklist shows that [Russia] had a motive. There is a serious motive for this thing. And there is a lot of circumstantial evidence pointing in that direction," Delev said.
The forensics report reviewed by RFE/RL noted evidence of "explosive fire" in each of the five warehouses Sage Consultants was using at Delev’s facility, but the protective earth barriers around each warehouse were virtually undamaged.
Delev said such destruction would be impossible if the incident had been triggered from a single location.
"Basically, these bases are built so that there is no detonating effect between the warehouses. In order for this thing to happen, the earth barriers that are specially built around each warehouse must be destroyed," Delev said.
"By simple logic, it transpires that there was some kind of interference, because everything was destroyed," he added.
Accusations Of Foot-Dragging
The calls by Dimitrov and ex-Defense Minister Shalamanov for a special parliamentary investigation into alleged cover-ups have so far gone unanswered.
But other Bulgarian officials have raised questions about the authorities' years of silence and lack of transparency about their investigations.
Bulgarian Prosecutor-General Ivan Geshev and his predecessor, Sotir Tsatsarov, have been accused by critics of stalling or thwarting investigations into possible Russian sabotage.
"The prosecution is doing all it can to cover up the tracks, to hamper the investigation," another ex-defense minister, Boyko Noev, told RFE/RL's Bulgarian Service.
He said that while Britain had hundreds of people investigating Skripal's Novichok poisoning, Bulgaria put just one or two investigators on the Gebrev case.
"This is among the evidence that shows that the prosecution then and now, and the executive authorities during the government of [former Bulgarian Prime Minister] Boyko Borisov, didn't want the truth to come out," Noev said. "There are many reasons, including Russia's influence over the [Bulgarian] special services and the prosecution."
Gebrev has accused Bulgarian authorities of refusal on multiple occasions to cooperate with friendly countries to investigate the GRU's alleged role in his poisoning.
Noev and other critics point to a supplementary cooperation agreement that Tsatsarov signed with his Russian counterpart in 2017 during an unannounced visit as an indicator that "Russia's influence over our authorities and the prosecution is undeniable."
Bulgarians are notoriously divided over NATO membership, and the country is widely regarded as one of the European Union's most Russia-friendly voices due in part to close historical, cultural, and economic ties.
Polls show a majority of the country wants its leadership to take a neutral position on the current Russia-Ukraine war.
The far-right, pro-Russian Revival party removed a Ukrainian flag from Sofia's City Hall building in May 2022 and has held rallies sympathizing with Russia's unprovoked invasion of Ukraine.
And in a country mired in political instability as it prepares for its fifth national elections in just two years, support for pro-Russian parties grew in the last vote in October 2022.
Former Defense Minister Shalamanov suggested there are officials in senior positions whose "interests are more connected to support for Russia and President [Vladimir] Putin than to Bulgaria's interests."
Others, including Noev and Bulgarian-born investigative journalist Christo Grozev of Bellingcat, are more blunt, effectively accusing the Prosecutor-General's Office of obstruction.
Grozev, who has reported extensively on GRU activities and is on a Russian Interior Ministry wanted list, alleged at a Bulgarian parliamentary hearing in January that authorities were withholding evidence of "probable" Russian sabotage in the ammunition-depot incidents.
RFE/RL requested details of Bulgarian investigations into the blasts from the Council of Ministers and the State Agency for National Security through the country's freedom-of-information laws. Both requests were denied.
But Bulgarian Prosecutor-General Geshev in January dismissed accusations of any cover-ups and said his office always cooperated with its partners.
"Concerning the blasts, what I can say is that we had very good communication with our Czech colleagues," Geshev told RFE/RL's Bulgarian Service after the parliamentary hearing in January. "I have talked on the phone with the former Czech prosecutor-general…and, believe me, all of the information that can be helpful for the Czech and Bulgarian side has been shared correctly."
RFE/RL asked Geshev whether there had been any developments in the investigations. In what appeared to be the first public acknowledgement of formal charges against any Russian nationals, Geshev told RFE/RL that six Russians had already been charged in connection with the blasts.
He said the six accused "are probably connected…to the Russian security services and are listed as wanted."
