The Russian army is facing fresh accusations that its soldiers have committed serious war crimes in Chechnya.

Video footage shot by a German journalist shows bodies of men believed to be Chechen fighters in a mass grave.

Many of them had been mutilated. Some were wrapped in barbed wire. Soldiers are seen throwing one body into the grave from a tank and dragging another behind a truck.

The pictures come after months of allegations of atrocities by Russian forces, which have repeatedly been denied by Moscow.

The images are already prompting renewed calls for a full international investigation into all the allegations of recent months.

"The Russian government has said consistently that our reports of summary executions and other abuses were lies," Human Rights Watch spokeswoman Minky Worden told BBC News Online.

"They just can't argue with this footage. It is entirely consistent with what our investigators have found from talking to refugees on the Chechen border.

"With evidence like this, there really should be no more pussyfooting around by the international community."

Ms Worden said economic sanctions such as the withholding of loan payments from the World Bank and the International Monetary Fund should now be imposed.

But British Labour MP Donald Anderson, chairman of the Foreign Affairs Committee, said he believed pressure would not affect Russian policy immediately.

"There is no way the tactics of the Russians will alter betwen now and the election," he told the BBC.

Unhindered

"Vladimir Putin relies on his reputation as a nationalist, as a strong man, and his electoral success depends on that."

The German journalist who took the pictures says he believes the troops themselves may disagree with the work they are having to do. He says this would explain the unhindered access he was given to the site of the mass grave.

Throughout Chechnya, Russian soldiers have been searching captured villages and towns for Chechen fighters.

Many men have been detained and their families have had no word on their whereabouts.

There was no immediate Russian reaction to the footage, but in Friday's Izvestia newspaper, Mr Putin vowed to continue the campaign.

In an "open letter" to electors, he said the Russian army was defeating what he called the "Chechen bandits" in a move towards establishing "a dictatorship of the law which is fair to all."