A Chechen rebel leader says he ordered a suicide bomb attack on a Moscow airport which killed 36 people.
The attack on the arrivals area of Domodedovo international airport on 24 January also left 180 injured.
Doku Umaro, one of Russia's most wanted men, made the statement on an Islamist website a day after threatening Russia with what he termed a year of blood and tears.
In a video posted online, the warlord said the attack was a response to "Russian crimes in the Caucasus" and similar suicide attacks would continue, the BBC reports.
Mr Umarov is leader of the "Caucasus Emirate", an Islamist militant group spanning the North Caucasus, and is one of the few prominent Chechen rebels still active, having served as security minister in the Chechen separatist government from 1996-99.
He has also claimed the suicide bombings on the Moscow Metro in March last year which killed 39 people, and is said to have ordered the November 2009 bombing of a train from Moscow to St Petersburg that left 26 dead.