Two people were killed and three injured in the town of Cetinje in Montenegro when an explosive device attached high in a tree was remotely detonated, police said on June 20.
The director of the Montenegrin police, Aleksandar Radovic, confirmed that the two deceased men, Petar Kaluđerovic and Dragan Roganovic, were members of organized criminal groups.
Radovic's deputy, Lazar Scepanovic, told reporters the attackers had monitored the victims' habits and knew they used armored cars.
The improvised explosive device used in the attack was placed 7 meters up in the tree, Scepanovic said. It targeted four people as they entered a sports center, he said.
Kaluderovic died at the scene, while Roganovic passed away in the hospital.
The injured are Tanasije Taso Jovanovic and Mihajlo Borozan, who were with Kaluderovic and Roganovic, and a passerby, Desanka Vujovic. All three injured men were transported to a hospital in Montenegro where they were treated for their injuries and their lives were not in danger.
Scepanovic said the attack is believed to be retaliation by a rival criminal group.
Radovic said the police had "intelligence that this could happen“ and "unfortunately, it came true."
He said the fight against organized crime is not easy, but the state will prevail, not crime.
State prosecutor Danka Ivanovic Deric said evidence had been collected at the site of the attack and police officers, forensic experts, and an explosives expert conducted the investigation.
The two men who were killed were known by the police force. Kaluderovic, 20, was arrested in April along with three others, including Borozan, on suspicion of illegal possession of weapons and explosive devices.
The police department said its officers had searched several properties in Cetinje "used by members of organized criminal groups and persons of security interest, and related individuals." At the time, the investigative judge ordered their detention but it was not clear why they were no longer in jail.
The other man killed in the explosion, Roganovic, was injured in December 2017 in Cetinje when he was shot while exiting a car. Roganovic had been the bodyguard of gang member Goran Radoman, who was killed in Belgrade in February 2015.
Radoman was one of the first victims in the war between rival gangs that have been operating in Montenegro for years. The clashes started in 2014 when around 250 kilograms of cocaine disappeared in Valencia.
The total number of murders in mafia clashes in Serbia and Montenegro since 2012 is 193, according to data from the Black Book, a joint project of the investigative network KRIK and RFE/RL.