Russian activists investigating the deaths of three soldiers say their findings indicate that elite army reconnaissance units are operating in Ukraine, adding to evidence of direct Russian involvement in the conflict there, despite repeated Kremlin denials.
The activists say they found fresh graves of soldiers from a special forces brigade of the Russian military's Main Intelligence Directorate (GRU), which is based in Tambov, a city 400 kilometers south of Moscow.
Their claims came shortly after Ukrainian authorities detained two men they say are GRU soldiers who were wounded in a firefight while on a scouting mission in eastern Ukraine, where fighting between government forces and pro-Russian rebels has killed more than 6,100 people since April 2014.
Activists Vadim Korovin, who posted pictures of the graves online, told AFP news agency on May 20 that the burials helped show that the Russian military is carrying out "large-scale reconnaissance operations" in eastern Ukraine despite a tenuous cease-fire.
The pictures placed on the Internet on May 19 are of two graves: one near Tambov and one in Tatarstan, a region on the Volga River. The graves show the date of death as May 5, 2015, and both have been adorned with identical wreaths from the Russian Defense Ministry.
A third soldier has been buried in a village in the southern Kurgan region bordering Kazakhstan, the activist said.
Russia denies it has sent troops into Ukraine, claiming that any Russian citizens fighting alongside separatists have gone there independently.
However, Korovin said the graves and information gathered from posts by grieving relatives and friends on social-networking sites indicate that the three men were not volunteers but Russian soldiers who were killed in Ukraine in the same place at the same time while on active duty.
Korovin, who is an assistant to opposition lawmaker Dmitry Gudkov, said he spoke by phone with the mother of one of the soldiers, Anton Savelyev, who was at first keen to meet but then changed her mind after a visit to the military base.
On May 19, Russia's Defense Ministry said the two Russians in Ukrainian custody, Yevgeny Yerofeyev and Aleksandr Aleksandrov, had left the military, but still insisted on their release. On May 20, Ukraine said it had charged them with involvement in "terrorist activity."
A report released last week, based on research begun by Russian opposition politician Boris Nemtsov before his killing in February, said that more then 200 Russian military personnel have been killed in the conflict in eastern Ukraine.