ed Russian province to the east of Chechnya, told Reuters by telephone that three interior ministry troops had been killed and 14 injured in a battle at the Chechen border that raged all night. Chechen border forces at the scene denied they were responsible for the attack. In a separate incident in Stavropol, to the north of Chechnya, four policemen were killed and a fifth was still missing after gunmen attacked their jeep at the Chechen border, a police duty officer told Reuters by telephone. The attack in Dagestan was the latest flare-up at a tense and heavily-armed border that has seen several major clashes in recent months. Itar-Tass news agency said the Russian forces in Dagestan had come under mortar attack throughout the night and had responded with "all types of weapons" including, by morning, helicopters firing rockets into Chechnya. But at the Chechen border post, the village of Azan Yurt 1.5 km (one mile) inside the region from the Dagestan border crossing, Chechen border guards said they had not fired back after Russians had opened fire on them. Salman Amayev, head of the Chechen border post, said if there had been any attack on the Russian border post it must have come from the Dagestani side of the border. He said there had been no reports of dead or wounded on the Chechen side. A Reuters correspondent saw one Chechen house freshly destroyed in what residents said was a Russian helicopter rocket attack. The area was quiet on Friday afternoon. Largely Moslem Chechnya claims independence from Russia, which withdrew its troops from the region after a humiliating defeat in a 1994-96 war that killed tens of thousands. Since the war, Chechnya and surrounding regions have been plagued by ethnic, religious and criminal violence. Moscow estimates that between 500 and 800 Russians are being held hostage by gangs in Chechnya. Russian Prime Minister Sergei Stepashin met Chechen President Aslan Maskhadov only last week. Ending violence along the frontier and kidnappings in and around the province was one of the main topics on their agenda. Russian news agencies quoted Maskhadov as saying on Friday that the overnight clashes were organised by people who hoped to scupper a planned meeting between him and President Boris Yeltsin set for coming weeks.BELGRADE (Reuters) - Yugoslav and Serbian officials said there was a security vacuum in Kosovo and called on peacekeepers to make the province safe for Serbs who have fled to return, the official Tanjug news agency reported on Friday. Serbia‘s Deputy Prime Minister Milovan Bojic blamed a security vacuum and inadequate coverage of the entire province by international peacekeepers for spurring Kosovo Serbs to leave. "(This) invoked insecurity among the Serbian population in that southern province so (the Serbs) started to back out," Bojic said. Bojic said the civilian defence headquarters was discussing the "delicate problem" of taking care of and eventually repatriating those who had fled Kosovo. Yugoslav troops are pulling out of the province and being replaced by international peacekeepers. International agencies had said that if there was a vacuum there could be an exodus of Serbs who feared revenge by ethnic Albanians. After days of ignoring the Serb exodus from Kosovo, at least in public, government officials began on Thursday to call for help and to urge Serbs not to leave Kosovo — considered the cradle of Serbian spirituality and culture. Opposition parties and the Serbian Orthodox Church have made similar calls but the refugees continue to pour out of Kosovo. Yugoslavia‘s Deputy Foreign Minister Nebosja Vujovic called for peacekeepers to make the province safe during a meeting on Thursday in Kosovo‘s capital Pristina with Lieutenant-General Sir Mike Jackson, commander of NATO-led forces in the province. Some 50,000 Serbs are thought to have fled Kosovo since ethnic Albanian refugees, themselves expelled en masse in what NATO says was systematic ethnic cleansing by Serbs, began returning over the weekend. Vujovic, who had a separate meeting with the U.N. undersecretary-general for humanitarian affairs, Sergio Vieira de Mello, also demanded that guerrillas of the Kosovo Liberation Army (KLA) be disarmed, Tanjug said. Vujovic accused the peacekeepers, described by Yugoslavia as a United Nations force, of failing to implement a military agreement reached early this month which led to the end of a 78-day NATO bombing of Yugoslavia. Tanjug quoted him as saying that the force "obviously is not undertaking necessary measures and concrete actions to eliminate the security vacuum and to provide for absolute security of Serbs, Montenegrins and other non-Albanian people of Kosovo and Metohija". Like most government officials, Vujovic used the Serbian name for the province which is the site of the Serbs‘ greatest battle, the birthplace of their national church and the site of their most majestic monasteries. Tanjug said Jackson considered the Yugoslav protest justified and pledged to do everything in his power to protect Serbs and Montenegrins, as well as proceed with disarming the KLA. De Mello arrived in Kosovo this week as a temporary U.N. special representative until a permanent candidate is chosen to head a civilian operation in the Serbian province to run in parallel with the NATO-dominated military one.