The car which blew up in a terrorist attack in the Russian North Caucasus region of Ingushetia was stolen in eastern Ukraine, local police said.
Two police officers were killed and another six injured in explosions carried out on Monday morning in the Ingush town of Karabulak.
The first blast was carried out by a suicide bomber, who set off an explosive device when he was stopped by security guards at the gates of a police station, killing two police officers and injuring another two.
"The second bomb, which was in a VAZ 2112 car parked opposite the police station in Karabulak, was activated by an unidentified person from a distance," police said, adding that the blast, equivalent to 50 kg TNT, occurred when an investigative group was inspecting the scene.
"The exploded silver VAZ-2112 car was stolen in the Ukrainian region of Donetsk."
Police could not explain how the stolen car, which was searched, was able to cross the Russian border and get into Ingushetia.
No one was killed in the second blast, but four were injured, including the deputy prosecutor of the Karabulak police.
On March 29, two deadly blasts occurred in two Moscow subway stations claiming some 40 lives and injuring dozens more. The attackers struck the Lubyanka and Park Kultury stations about 40 minutes apart during the morning rush hour.
Chechen militant leader Doku Umarov claimed responsibility for the metro attacks, saying in a video message they were revenge for a special operation carried out by federal security forces on February 11, 2010, when 18 militants and four civilians were killed in Ingushetia. He threatened further attacks.
Two days after the Moscow subway blasts another two explosions occurred in the town of Kizlyar, in Dagestan near the border with Chechnya, killing 12 people and leaving 29 injured.
The Russian counter-terrorism committee said the organizers of the recent terrorist attacks in Moscow and Kizlyar and some of the suicide bombers have been identified.
President Dmitry Medvedev said the bombings were all links in the same chain, while Prime Minister Vladimir Putin said a single terrorist group carried out the attacks.
Russia has been fighting militants in the North Caucasus for almost two decades, including two brutal wars against separatists in Chechnya.
MOSCOW, April 5 (RIA Novosti)
