VLADIKAVKAZ - Six Russian servicemen were killed in rebel attacks on federal positions and clashes with insurgents over the past day, an official said Saturday.

Rebels attacked Russian outposts and positions 16 times over the past 24 hours, leaving two Russian soldiers dead and seven wounded, the official in the Moscow-backed Chechen administration said.

Three military reconnaissance servicemen were killed and eight were wounded in a clash late Friday with rebels near the town of Shali, 25 kilometers (16 miles) southeast of the capital Grozny, the official said, speaking on condition of anonymity.

Rebels opened fire on a military vehicle near the village of Gerzel in the Gudermes region east of Grozny on Friday, killing one Russian soldier and wounding another, the official said.

In the town of Sharoi in southern Chechnya, the body of a police officer with numerous bullet wounds was found early Saturday, the official said. Details of his death were not immediately available.

At least 130 people suspected of giving aid to the rebels were detained in security sweeps in operations in Grozny, Shali and the southern Vedeno district over the past 24 hours, the official said.

Chechen civilians and human rights advocates have strongly criticized the military sweeps, saying they frequently lead to beatings, unjustified arrests and disappearances of people who have no rebel connections.

The rebels are outnumbered and outgunned by Russian forces but almost daily stage hit-and-run attacks on Russian positions and regularly target Russian troops and Moscow-backed Chechen officials with mines.

Russia's first war in Chechnya from 1994-96 ended when Russian forces pulled out after a failed 20-month campaign against the rebels.

Russian troops returned to Chechnya in 1999, after rebels launched an incursion into a neighboring republic and after a series of apartment house bombings in Russia, blamed on rebels, that left some 300 people dead.

In Moscow Saturday, about 500 people staged a demonstration against the war in Chechnya, calling on the government to halt its offensive and cancel plans to hold a constitutional referendum in the republic next month.

The demonstrators, who marched to Pushkin Square, chanted and waved anti-war signs. The march was organized by three liberal political parties, Liberal Russia, Yabloko, and Union of Right Forces, NTV television reported.