Security forces are searching for an ethnic Russian member of a North Caucasus Islamist group suspected of involvement in the Moscow airport bombing which killed 35, a leading daily reported on Thursday.
Monday's suicide attack in the arrivals hall of Moscow's Domodedovo airport bore the hallmarks of Islamist insurgents from the North Caucasus. No group has claimed responsibility, which left some 130 injured.
The daily Kommersant, citing unnamed security sources, said the wanted man was named Razdobudko and a resident of the Stavropol province, which borders on provinces of the North Caucasus inhabited by mostly Muslim non-Russian ethnic minorities.
It said Razdobudko was believed to be a member of the Nogai Jamaat, an insurgent group based in Dagestan, a province at the heart of a growing Islamist insurgency fueled by two post-Soviet separatist wars in neighboring Chechnya.
He may have organized the attack or even been the suicide bomber himself, the report said.
The insurgency has attracted few ethnic Russians, but some switched sides during the second war between federal forces and Chechen separatists a decade ago. Ethnic Russian members of Islamist groups have been blamed for previous attacks.
The Nogai Jamaat, or Nogai Group, was responsible for a New Year's Eve suicide bomb plot in Moscow, Kommersant said, that was foiled when a cellphone text message detonated the female attacker's bomb prematurely, killing her in her apartment.
The Nogai region is in northern Dagestan, close to Stavropol.
Dagestan is the site of frequent attacks. A car bomb blast late on Wednesday killed four people and injured three others outside a cafe in the Dagestan town of Khasavyurt, near the border with Chechnya, authorities said.
Prime Minister Vladimir Putin has vowed "retribution" for the airport bomb attack. Among the dead were at least eight foreigners.
President Dmitry Medvedev said on Tuesday that groups behind such attacks must be destroyed and told security forces an increase in terrorist attacks in 2010 was a strong signal that they must do a better job.
A picture of the alleged suicide bomber has been distributed to police stations across Russia, Interfax news agency quoted a law enforcement official as saying on Thursday.