Chechen rebel leader Doku Umarov has said his group was behind Monday's double suicide bombings on the Moscow Metro, which left 39 people dead.
In a video message posted on a Chechen rebel website, he said he had personally ordered the attacks.
He said they were carried out in retaliation for the killings of "poor Chechen and Ingush residents" by the Russian security forces in February.
Doku Umarov also warned Russia to prepare for more attacks.
Russian investigators have said they believe two female suicide bombers were linked to militants in the North Caucasus.
Prime Minister Vladimir Putin has called on the security forces to "scrape from the sewers" those responsible for the Moscow attacks.
Chilling message
In the video posted on the www.kavkazcenter.com website, Doku Umarov said the Moscow attacks were an act of revenge for the killings of Chechen and Ingush civilians by the Russian security forces near Arshty on 11 February.
The rebel, who styles himself as the Emir of the Caucasus Emirate, said attacks on Russian soil would continue.
"The war will come to your street... and you will feel it on your own skins," he warned Russian citizens in the video which he said was recorded on Monday - just hours after the Metro attacks.
Earlier on Wednesday, Doku Umarov's spokesman had told Reuters that his militant group "did not carry out the attack in Moscow, and we don't know who did it".
BBC News
