A female suicide bomber killed five policemen late Tuesday at a checkpoint in Russia's troubled Dagestan region.
Officials say the attack took place in the village of Karabudakhent.
The official Itar-Tass news agency says police found the bomber's severed head close to the scene. No one has claimed responsibility for the attack.
Dagestani police and authorities suffer from almost daily attacks from Muslim insurgents fighting to set up an Islamic state inside Russia's Caucasus region.