An obscure Islamic group claimed responsibility Thursday for the assassination of a mayor in Russia's troubled North Caucasus, saying he had sanctioned persecution of Islamic women.

It was impossible to verify the claim by the group, Kataib al-Khoul — posted on a Web site allied with insurgents in Chechnya, which neighbors the region of North Ossetia.

North Ossetian police officials said they were investigating the claim along with other theories, including that Vitaly Karayev, mayor of the North Ossetian capital of Vladikavkaz, was killed in connection with other business activities.

The North Caucasus has been roiled by years of insurgency in Chechnya, rampant corruption and this summer's war in neighboring Georgia.

Officials said Karayev was shot in the heart by a sniper Wednesday morning as he got into his car to go to work.

The claim of responsibility was posted on Kavkaz Center, a Web site used as a mouthpiece for rebels fighting Russian forces and allied paramilitaries in Chechnya and other North Caucasus regions.

The group said Karayev was killed because of orders he gave following a bus stop bombing earlier this month that killed 12 people. It was unclear what the order entailed and city officials could not be immediately reached for comment.

According to the statement, "due to his instructions the harassment of Islamic women in headscarves was authorized which resulted in their being insulted and belittled in public places and on public transport."

"The execution of this enemy of Allah was carried out by a (deputy) of the emir of Kataib al Khoul," the statement said.

Prosecutors had said a female suicide bomber might have been responsible for the explosion Nov. 6 at the bus stop, but no final conclusions have been released.

North Ossetia borders Georgia, which fought a short war with Russia in August. It also borders the Russian region of Ingushetia. Ingush, who are mostly Muslim, make up small proportion of North Ossetia's largely Orthodox Christian population.