Stressing that Milosevic should comply with the October cease-fire pledge, NATO Secretary-General Javier Solana warned that ``otherwise he will face reality,'' indicating the 16-member military alliance will not hesitate to take affirmative action against Serbian forces, which have been pounding Albanian rebel targets for the last two days.

``There is no question that regional responsibility lies on the shoulders of President Milosevic'', Solana said in Brussels adding, ``he bears the majority of responsibility''.

However, Solana also admonished the Kosovo Liberation Army (KLA) rebels, fighting to free Kosovo from Serbia, to stop hostilities and participate in talks aimed at finding a diplomatic solution for the conflict in Kosovo.

Top NATO commanderWesley Clark, one of the two generals ordered by NATO yesterday to deliver a strong message to the Yugoslav president, is already on his way to reiterate Solana's demands in talks with Milosevic in Belgrade.

NATO officials said the general would also press Milosevic to adhere to the promises made by Serbia in October, when a eleventh-hour peace deal suspended threats of air strikes against Yugoslavia.

Tensions rose in Kosovo, an autonomous region of the Serbian republic and part of the former Yugoslavia, after 45 Albanians were found dead in Racak village on Friday. Western monitors in the region accused Serbian forces of massacring civilians in the name of crackdowns against rebels.

Hundreds of people have been killed and hundreds of thousands more displaced by fighting between the ethnic Albanian rebels and Yugoslav forces in the region since last February.

Meanwhile, even as NATO was issuing a second warning, reports from Kosovo said Serbian forces continued shelling Racak village from thesurrounding hills. The police have also sent large numbers of armoured vehicles into the region to fight the rebels.

Yugoslav border guards also refused to allow Louise Arbour, chief prosecutor of the UN war crimes tribunal to enter the country from Macedonia to investigate Friday's massacre in which three women and a 12-year-old boy were also killed.

Russia cautions against `hasty accusations'

Two prominent Russian lawmakers warned today against hastily accusing Serbian forces of the recent massacre in Kosovo. They said investigators should consider the possibility it was a provocation designed to smear the Serbs. US diplomat William Walker, who heads the Organisation for Security and Cooperation in Europe (OSCE) peace mission in Kosovo, has accused Serb forces of the killings. But Gennady Seleznyov, speaker of the lower house of Russia's parliament, said, ``Nothing can be ruled out.'' ``We know plenty of cases when provocations were intentionally organised, when people were killed to put theblame on one of the conflicting sides,'' Seleznyov, a Communist, told the Interfax news agency. ``Everything should be very thoroughly examined.'' Vladimir Lukin, who heads parliament's international affairs committee, expressed a similar view.