Between 200 and 400 Russian soldiers took control of Pristina airport when they entered Kosovo ahead of Nato troops on Saturday.

The Russians have refused British forces in Pristina, the regional capital, access to the airport, seen as a possible headquarters for peacekeeping operations.

But the advance force, which travelled to Pristina from Bosnia, arrived in Kosovo with limited supplies and has been running out of water.

The reinforcement brigade joined up with armoured vehicles from D Squadron of the Household Cavalry at 0800 local time (0700 BST).

They met 20 miles north of Pristina - the furthest north that UK troops have so far ventured.

Nine Russian vehicles were in the convoy carrying fuel, food, water and medical supplies.

Burning villages

The mission was intended to show co-operation between Russian and British forces in K-For, the UN-backed international peacekeeping operation for Kosovo, despite the political controversy over the Russian presence at the airport.

Nato and Russian generals have tried unsuccessfully for several days to resolve the stand-off

And US and Russian politicians have tried to negotiate a political solution - so far without success.

British troops driving north to meet the Russian convoy passed several burning houses.

Most of the villages they passed through were destroyed and some buildings were sprayed with bullet holes.

They also came across columns of Yugoslav troops driving north as part of the withdrawal process, and were accompanied by Serb families who are also leaving the province.

War crimes

Elsewhere, British war crimes investigators have begun work at the site of an alleged mass grave in Kacanik, southern Kosovo.

War crimes investigator David Gowan: "It's chilling"

UK War Crimes co-ordinator David Gowan and Metropolitan Police Detective Chief Superintendent John Bunn will pass evidence to the War Crimes Tribunal in The Hague.

Mr Gowan told the BBC: "At Kacanik, we found very chilling evidence of atrocities.

"We found a lot of graves and there was a smell of decomposition. It was a very ugly scene indeed."