A suicide bomber today killed at least six policemen and injured another 14 people in Russia's southern region of Dagestan, where Russia is fighting an escalating Islamist insurgency.
The upsurge of violence in the Muslim-dominated North Caucasus has become Russia's single biggest domestic problem, according to President Dmitry Medvedev, and many observers are concerned the violence could spread to Russia's heartland.
The suicide bomber drove a car into a special traffic police depot in Dagestan's capital of Makhachkala but was blocked in by another police vehicle before exploding, local news agencies said.
A police spokesman was quoted as saying that casualties would have been significantly bigger if the car had not been blocked in by the police officers who were killed in the resulting explosion.
Over the past year, the patchwork of republics along Russia's southern flank have seen a wave of attacks which local leaders say are fuelled by a potent mixture of clan feuds, poverty, Islamism and heavy-handed tactics by law enforcement agencies.