MOSCOW — Russia’s counterterrorism agency said Monday it is studying a video posted by an Islamic militant group that asserted responsibility for suicide bombings that killed 34 people last month and that threatened to strike the Winter Olympics in Sochi.
Security analysts say the Russians are right in taking the threat seriously.
The video was posted online Sunday by a militant group in Dagestan, a predominantly Muslim republic in Russia’s volatile North Caucasus. The Olympic host city of Sochi lies only 300 miles west of Dagestan.
Two Russian-speaking men featured in the video are identified as members of Ansar al-Sunna, the name of a Jihadist group operating in Iraq.
It was unclear whether the men in the video had received funding or training from that group or only adopted its name.
There was no confirmation the two men were the suicide bombers who struck the southern Russian city of Volgograd last month as the video says.
Scores of people were also injured by the bombings of a train station and a bus.
Russia’s National Anti-Terrorism Committee said Monday it was studying the video and would have no immediate comment.
The video could not be viewed in Russia, where Internet providers cut access to it under a law that bans the ‘‘dissemination of extremist materials.’’
It was released by the Vilayat Dagestan, one of the units that make up the so-called Caucasus Emirate, an umbrella group for the rebels seeking to establish an independent Islamic state in the North Caucasus.
Doku Umarov, a Chechen warlord who leads the emirate, had ordered a halt to attacks on civilian targets in 2012.
But he rescinded that order in July, urging his followers to strike the Sochi Olympics, which he denounced as ‘‘satanic dances on the bones of our ancestors.’’ The games run from Feb. 7 to 23.
The Kremlin-backed leader of Chechnya said last week that Umarov was dead, but the assertion could not be verified.
The Vilayat Dagestan statement said the Volgograd attacks were carried out in part because of Umarov’s order, but it did not specifically say he had ordered them.