Russia's Interfax news agency said the six police officers were killed in an attack on a funeral service for a fellow officer on Sunday.

The report said an explosive device went off at a house in the town of Malgobek where mourners had gathered. It said several people, including civilians, were injured.

The funeral was for an officer killed in a shooting on Saturday evening in the Malgobek region.

The regional Investigative Committee said in a statement that a suicide bomber was behind the attack.

"In a private house where the funeral was taking place for a neighborhood policeman, the bomber triggered an explosive device on his body," the statement said. "As a result of the explosion, according to preliminary information, seven people died including the suicide bomber."

Russian security forces in the Caucasus often suffer attacks that they blame on Islamist militant separatists with links to Chechnya, where Russia has fought two wars over the past 20 years.

On Friday, four members of a Russian anti-terrorist unit were shot dead in Chechnya itself.

Mosque attack

The explosion came just hours after masked gunmen opened fire in a mosque in the town of Khasavyurt in the nearby Caucasus republic of Dagestan, injuring at least eight people.

Citing local police, RIA Novosti news agency said more people were hurt in an explosion in the same mosque after the gun attack. It said two explosive devices were left in the mosque by the attackers, one of which was defused.

Police however told Interfax that no one had been injured in an explosion, although they said experts were working to defuse one explosive device.

The attack came as worshippers prepared to celebrate the Eid al-Fitr holiday - known as Uraz-Bairam in Russian - that marks the end of the fasting month of Ramadan.

tj/msh (dpa, AFP)