Suicide bomber kills two policemen in Russia

A suicide bomber killed two policemen and wounded a third near the police headquarters of a town in Russia's North Caucasus region of Ingushetia on Monday, officials said.

The bombing in Karabulak, about 20 km (12 miles) from the regional capital Magas, followed suicide attacks in Moscow and the Dagestan region of the Caucasus over the past week that killed 50 people.

"According to preliminary information a suicide bomber set off an explosion outside the town's police station," said a spokesperson for the local interior ministry.

"Two policemen were killed and one was injured and is now being treated in the hospital," the spokesperson said.

Officials said Karabulak was rocked by a second blast at the scene of the suicide bombing. 

Fears of a new bombing campaign against the Russian heartland intensified after a twin bomb attack on a railway line in Dagestan on Sunday that security forces said was linked to the other attacks.

Ingushetia is plagued by almost daily attacks targeting law enforcement authorities, part of an upsurge in violence in Russia's North Caucasus a decade after the second of two wars pitting government forces against Chechen separatists.

Officials blame Islamist militants for the violence, but local residents and rights activists say it is fuelled by government corruption and other factors.

On Wednesday, Chechen rebels claimed responsibility for the Moscow metro bombings and threatened further attacks against Russian cities.