The attacks come a day after the former head of an administrative district in Dagestan was killed in the town of Khasavyurt, near the Chechen border.

Suicide bombing

Russia's mainly Muslim North Caucasus region has experienced a rise in violence in recent months, with Islamist separatist fighters launching attacks on the pro-Kremlin local authorities.

In August, a suicide bombing in Ingushetia killed at least 20 people and wounded more than 70 others in an attack on a police station.

The rising violence throughout the North Caucasus is undermining the Kremlin's claims to be enforcing effective law and order in the region.

While large-scale fighting from the two wars that ravaged Chechnya since 1994 has ended, rebel fighters continue to mount hit-and-run attacks and skirmishes with Russian and Chechen security forces.