The Russian military says this letter was addressed to London

Documents, letters and videotapes found after a gun battle suggest the men were recruited in Britain, Moscow said.

It said the militants were part of a group of 10 rebels fighting east of the Chechen capital, Grozny.

Three members of the group died in a fierce gun battle with Russian troops and two had documents from the UK.

The BBC's Steve Rosenberg in Moscow reports one of the victims, an Algerian by birth, is alleged to have been found with a travel document issued by the UK immigration office.

Foreign fighters

A second fighter was found with a letter addressed to his sister in London, suggesting he had links to London's Finsbury Park mosque, the military said.

Officials believe both men had been recruited in Britain and went to Chechnya via Azerbaijan and Georgia.

Moscow has called on UK authorities and other governments to do more to prevent the recruitment of militants.

It has regularly accused foreign fighters of providing support to Chechen rebels since launching its so-called "anti-terrorist operation" in the North Caucuses more than four years ago .

Officials say they found a passport

In October 1999, the then prime minister and now Russian President Vladimir Putin launched an "anti-terrorist operation".

He blamed Chechens for apartment block bombings in Moscow and other Russian cities.

Since the siege of a Moscow theatre in October 2002, when Chechen fighters took hundreds of people hostage, a series of suicide bomb attacks have been made against Russian targets.