(MOSCOW) -- A leading Chechen militant has claimed responsibility for the Jan. 24 suicide bombing of Moscow's Domodedovo airport that killed 36 people and injured scores more.
Appearing in a 16-minute video released on the Internet, Doku Umarov claims the "martyr operation" was carried out on his orders.
In the video, Umarov says the Muslims of the Caucasus were at war with the Russian "occupation" and says the attacks will continue, according to Kavkaz Center, a Chechen news outlet that posted the video statement from Umarov.
While the Chechen's claim of responsibility has not been verified, a senior U.S. official told ABC News Umarov's past claims of responsibility gave him credibility. "We would not be surprised to learn that he is in fact behind the [airport] attack," the official said.
The bombing targeted the arrivals area of the Domodedovo airport at 4:40 p.m. Moscow time Jan. 24. In addition to the 36 dead, another 130 were injured in what investigators called a suicide bombing at the country's busiest airport.
Initial reports published by Russia's state news agency RIA said witnesses had seen two suicide bombers carry out the attack. Later reports pointed to a single attacker. On Twitter, one purported eyewitness, Ilya Likhtenfeld, said the bomb was on a man standing in a crowd near a cafe.
Video taken inside the airport apparently minutes after the bombing shows the blast area full of smoke, with luggage scattered around the ground. Several bodies, prone and unmoving on the ground, are also visible.
No hard evidence has emerged yet to link the Domodedovo bombing to any specific terrorist group, but, according to former White House counter-terror adviser and ABC News consultant Richard Clarke, it fits the pattern of a persistent Chechen campaign of violence.
"This is part of a pattern where the Chechen rebel group attacks in Moscow or in Russia -- a major attack about every two years," Clarke told ABC News following the bombing. "They've attacked in the Metro, they've attacked in schools, they've attacked in apartment buildings. This is a regular pattern."
Suicide bombers, often female, from Chechnya or Dagestan and sometimes known as "black widows," have carried out many attacks on Russian targets in the past decade, including the simultaneous bombings of two planes mid-flight that killed 90 people in the summer of 2004 and a Moscow Metro bombing that killed 10 a week later.
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