After a rapturous welcome in Pristina city centre by thousands of people, troop transports and trucks carrying several hundred Russian soldiers headed for the airport, saying they were to prepare the arrival of Russian planes. They, however, showed no sign of obeying a recall order which Ivanov said had been issued by Moscow.

The Russians appeared to have flouted a reported agreement not to enter Kosovo before western elements of the NATO-led peacekeeping force (KFOR) did so, following the retreat of Serbian forces.

The move clearly caught the North Atlantic Treaty Organisation on the hop, with a White House official saying that United States Deputy Secretary of State Strobe Talbott, currently in Moscow, hadcontacted Russian officials to obtain clarification.

White House spokesman Mike Hammer was also quoted by Russia's ITAR-TASS news agency as saying that close aides of US President Bill Clinton had urged him to speak to his Russian opposite number Boris Yeltsin, without saying whether this had happened.

Hammer also told AFP that ``We have no reason to doubt that there will be an immediate withdrawal'' of the Russian troops and that ``this was an unfortunate set of circumstances''. He added that Talbott had received these assurances from Ivanov.

Talbott was in Moscow to negotiate Russia's role in a NATO-led international peacekeeping force for Kosovo (KFOR) and had received assurances earlier that Russian troops would not enter Kosovo ahead of KFOR.

In a recorded interview broadcast on PBS television only minutes before the Russian arrival was reported in Pristina, Clinton said he did not foresee any major problem with Moscow over Kosovo.

The Russians entered Pristina shortly before 1:30 am (GMT) onSaturday to be greeted by thousands of people shouting, ``Serbia, Serbia''. Shots were fired in the Air, and both soldiers in the convoy and welcoming youths who were allowed to scramble aboard the trucks gave the traditional three-fingered Salutation of the Orthodox Church.

The convoy made a brief halt in the suburb of Kosovo Polje, three kilometres (two miles) from the city centre, before taking the only road to Pristina's airport. One of the soldiers in the Russian contingent, Yevgeny Sadovsky, said, ``We have come to prepare the airport for the arrival of Russian aircraft and then we will depart''. Sadovsky said the troops expected to stay for two weeks.

-- Agence France Presse