Two suicide bombers have struck in Russia's southern republic of Dagestan, killing at least 12 people, just two days after deadly suicide attacks in Moscow.
Wednesday's blasts occurred in the town of Kizlyar, near Dagestan's border with Chechnya. At least nine police officers were among the dead, including the town's police chief. At least 23 people were wounded.
Dagestan's interior minister says the first suicide bomber detonated explosives when traffic police tried to stop the car he was in. A second bomber dressed in a police uniform set off the other blast as police and residents gathered around the scene of the car bombing.
On Monday, twin suicide blasts on the Moscow subway system killed 39 people.
Russian Prime Minister Vladimir Putin says a single terrorist group may be behind both the Moscow and Dagestan attacks.
Authorities have said the bombings in Moscow were carried out by two women with links to Islamist insurgents in Russia's restive southern republics.
There has been no official claim of responsibility for the attacks.
The head of Russia's Security Council, Nikolai Patrushev, was quoted as telling the Russian Kommersant newspaper that Russia is investigating possible Georgian involvement in the metro bombings. He said Russia has information that agents of Georgia's special forces maintain contacts with terrorist groups in the North Caucasus.
Georgian officials criticized Russia for the statements. But Georgia's minister for reintegration, Temur Yakobashvili, said Wednesday that Georgia is ready to cooperate in any investigation.
On Tuesday, Russia observed a day of mourning for the victims of the Moscow blasts, and President Dmitri Medvedev called for Russian courts and lawmakers to find new ways to strengthen anti-terror laws.
Russian media say police were searching Tuesday for two women and a man seen with the female bombing suspects on surveillance video shortly before the attacks occurred.
Last month, Chechen rebel leader Doku Umarov vowed to take the battle for Chechyna's independence to Russia's cities.