(CNN) -- Russian police have identified two people they believe are the suicide bombers responsible for deadly bombings in Volgograd and detained two suspected accomplices, anti-terrorism officials said Thursday, according to Russian state news agency Ria Novosti.
The National Anti-Terrorism Committee identified the suspected suicide bombers as Asker Samedov and Suleiman Magomedov. It said they belong to the Buinaksk militant group, based in the volatile southern Russian province of Dagestan, according to Ria Novosti.
The two accomplices who are detained are brothers, both from Dagestan, and they are held on suspicion of assisting the suicide bombers in traveling to Volgograd, it said.
The Volgograd twin bombings, which took place in December, killed 34 people and injured many others, heightening concerns about security in Russia before it hosts the Winter Olympics, which open in just over a week.
Huge security operation
The Games are set to begin on February 7 in Sochi, and a huge security operation is under way around the Black Sea resort.
Russia is pouring resources into ensuring that the Olympic Games, seen as a flagship project of President Vladimir Putin, go off without problems.
A bitter battle for an independent Chechnya, lasting almost two decades, spawned an insurgency that has spilled into neighboring republics in the North Caucasus region, including Dagestan.
Chechen warlord Doku Umarov, leader of the Islamist group Caucasus Emirate, last summer called on his followers to do what they could to disrupt the Games. He has said they will be held on the graves of Muslim occupants of Sochi, who he says were driven out by Russian imperial forces in the 19th century.
Despite the shock waves from the Volgograd attack, International Olympic Committee President Thomas Bach said he was confident that Russia would keep the Winter Olympics safe.