The Council of Europe has called for an investigation into new allegations that Russian troops have executed civilians in Chechnya.

The allegations were contained in a report by the New York-based group, Human Rights Watch, which said it had confirmed that 38 civilians had been executed in a district of the Chechen capital, Grozny - including nine members of one family.

A senior Russian commander, General Valery Manilov, rejected the accusations, saying there was no proof to back them up.

Meanwhile, Russian forces continued their attacks on rebels holding out in the mountains of southern Chechnya.

The Chairman of the Council of Europe Parliamentary Assembly, Lord David Russell-Johnston, said the Human Rights Watch report was "alarming".

"Not only must these reports be investigated, the perpetrators must be brought to justice and the Russian authorities must take action to prevent such acts being committed," he said in a statement issued in Strasbourg.

Human Rights Watch posted a report on its website on Friday which said it had examined the mutilated corpses of three more executed Chechen civilians, bringing the total found in one district of Grozny to 41.

Eyewitness reports

The organisation is investigating a number of other reported cases.

Its report published on Thursday gives detailed accounts by eyewitnesses of the deliberate killing of individual civilians.

They say some were shot at short range, while others were burned, or attacked with grenades.

Russian war planes have been continuing to pound rebel positions in the south of the republic, as Moscow prepares to send 50,000 troops into the mountains.

According to Russia's North Caucasus headquarters, Russian bombers and helicopter gunships have been carrying out hundreds of raids in the Argun and Vedeno gorges south of Grozny.

The Chechen leader, Aslan Maskhadov, has warned that his forces are beginning an all-out guerrilla war against the Russians.

But General Manilov, first deputy chief of Russia's General Staff, described Mr Maskhadov's threat as a bluff, and said the Chechens did not have the support of the Chechen people.

Troop cut

He said Russia was planning to cut its forces in Chechnya by nearly half.

"There will be about 50,000 troops left, and they will be mainly paratroops, marines and rapid reaction forces," General Manilov told ORT television.

"They will be people trained to fight in mountains," he said. "Enough troops will remain to deal with the situation."

Last week, Russian officials said the force in Chechnya numbered 93,000.