British paratroops and Gurkhas on board Chinook helicopters were the first Nato soldiers to enter the province, at 0305 GMT. Wave after wave of Chinooks, supported by US Apache helicopters led the way, crossing into Kosovo airspace from the Former Yugoslav Republic of Macedonia. Beneath them, thousands of troops lined up in convoy,began crossing the ground border at Blace - the same frontier post used by thousands of Kosovo Albanian refugees as they fled President Slobodan Milosevic's programme of ethnic cleansing. Brigadier Adrian Freer, commander of the British 5th Airborne brigade and the first Nato officer to cross the land border at Blace, said: "We're going in to secure peace and make peace." The deployment is one of the biggest military operations in Europe since World War II. It is intended to help thousands of refugees return home, though they have been warned they will have to wait until the province is made safe. Although the international peacekeeping operations was launched with the authority of the United Nations, most of troops are from the Nato nations which carried out the air campaign against Yugoslavia. British units are being joined by French and German forces - the advance guard of a force that will eventually number about 50,000. French troops, led by mine-clearing experts from the French ForeignLegion, moved into Kosovo along two lines of advance several kilometres apart and to the east of Blace. Military sources said part of the advance was held up when special forces commandos detected a minefield just a few hundred metres into Kosovo. Russian surprise Hours earlier, Russian troops had been given a heroes' welcome by cheering crowds of Serbs when they unexpectedly arrived in Pristina. In a remarkable turnabout, Russian Foreign Minister Igor Ivanov immediately ordered them back out again. Ivanov called the move "unfortunate" and said they had been ordered to leave Kosovo. He said the troops did not have government authorisation to enter Kosovo. White House spokesman Joe Lockhart said the Russian explanation has been accepted. The column of Russian armoured cars, trucks and troop transporters drove through the city centre and were later reported parked on the road to the airport.

A Russian solder said they had come to "prepare the airport for the arrival of Russian aircraft andthen they would depart". He expected the unit would be there for two weeks. Vital road Paratroopers and Gurkhas immediately began securing the landing zones and high ground above the road to Pristina. By 0800GMT the most forward unit was 20 miles (30km) along the road towards Pristina.

American forces have also been involved in the first stages of the operation to enter Kosovo from Albania and Macedonia. Nato officials have planned for a "substantial" force to be in Kosovo by Saturday afternoon but have not released details of the operation. In the hours before the troop movement, a British transport plane crashed on a military airfield near the Albanian town of Kukes, injuring one person. Moscow's pledge Russia's role in K-For, a UN operation, but whose manpower is predominantly from Nato nations, has not been fully determined.