俄罗斯研究威胁冬奥会的激进组织视频

Russian security forces are studying a video posted by an Islamic militant group that claims responsibility for last month's suicide bombings in Volgograd, and threatens attacks at the upcoming Olympics in Sochi.

The video was posted online Sunday by a militant group from the predominately Muslim region of Dagestan. It is unclear when the video was made.

In the video, two Russian-speaking men warn President Vladimir Putin to expect what they call a "present" at the Sochi Winter Olympics. The video says the two men are the suicide bombers who attacked Volgograd last month, killing 34 people. There is no independent confirmation of that claim.

The U.S. military said Monday it will make available air and naval support to the Russian government as it makes security preparations for the Olympics. A Pentagon spokesman said in a statement that support including two U.S. Navy ships in the Black Sea will be available, if requested, "for all manner of contingencies" in consultation with the Russian government.

In another development, hotel workers in Sochi tell reporters they have seen wanted posters for a woman from Dagestan. She is described as a 22-year-old widow of a militant killed by Russian security forces last year. The posters say the woman ((identified as Ruzanna Ibragimova)) may be in or near Sochi and could be planning an attack.