The Islamist group "Emirate of the Caucasus" has claimed responsibility for this week's Moscow metro bombings, a Chechen Internet site said on Wednesday.

In a video statement recorded on Monday, the leader of the group, Doku Umarov, said the purpose of the attack had been to avenge "the massacre by Russian invaders of the poorest residents of Chechnya and Ingushetia, who were picking wild garlic in the Arshty village on February 11, 2010, to feed their families."

In the video, which was also reported by the SITE monitoring group, Umarov warned of fresh strikes against Russia, saying soldiers stabbed their victims to death and then "mocked" their corpses. He told Russians that "war will come to your streets, and you will feel it with your own lives and skins."

Putin vows capture

The video - the authenticity of which couldn't be independently confirmed - was the first claim of responsibility for Monday's metro bombings in Moscow that killed 39 people.

In response, Prime Minister Vladimir Putin ordered security forces to apprehend the masterminds, saying they would be caught even if police had to "scrape them from the sewers."

Police have already released photographs of the two bombers' severed heads. Unconfirmed reports suggest they arrived in Moscow from the Caucasus by bus early on Monday.

glb/Reuters/AFP

Editor: Susan Houlton