Investigators suspect that a militant Islamist group from the North Caucasus was behind the attack on Moscow's Domodedovo airport in which 35 people died, Russian media reported Thursday, DPA reported.
The prime suspect was a man from the southern Russian region of Stavropol who could have either organized or carried out Monday's blast, the Kommersant newspaper quoted police as saying. They linked him to the Nogay Jamaat terrorist group.
The Stavropol region adjoins the North Caucasus - which includes the republics of Chechnya, Ingushetia, Dagestan, North Ossetia and Kabardino-Balkaria.
Numerous radical Islamist groups have been fighting for an independent "emirate" in the North Caucasus for years as the Kremlin has struggled to impose peace on the region, plagued by poverty and high unemployment.
Police were looking for 10 additional suspects in connection with the attack in the arrival hall of Moscow's busiest airport. No group has yet claimed responsibility for the blast.
Meanwhile, the president of Chechnya, Ramzan Kadyrov, said the international community had a tendency to point fingers, without having all the facts.
"They are always in a hurry to tell the whole world that the Caucasus is a place where there is no order and people are ready to kill anyone, as if we all are murderers and terrorists," Kadyrov told broadcaster Russia Today.