Officials said five policemen were killed in the attack on Saturday, when assailants opened fire on the police station from a car.

"Several Chechen separatist guerillas were destroyed. There are losses among pro-Russian servicemen too," a spokesman for the Russian forces in the North Caucasus, Major-General Ilya Shabalkin said.

Several other people were also wounded in the attack.

The ITAR-TASS news agency reported two policemen and three civilians killed.

War-torn Chechnya is to hold a presidential election on 29 August, after its pro-Russian leader, Ahmad Kadyrov, was killed in a bomb attack last May.

Russian troops marched back into the breakaway republic to put down a separatist rebellion almost five years ago, sparking a still ongoing conflict.