BRUSSELS (Reuters) - NATO officers were set to meet representatives of the Yugoslav general staff in Macedonia on Monday for further contacts on the stalled withdrawal of Serbian forces from Kosovo. The contacts will follow the suspension of weekend talks between NATO‘s commander in Macedonia, British General Mike Jackson, and Yugoslav army commanders. At the same time, NATO has stepped up its air campaign to its former intensity. NATO spokesman Jamie Shea told reporters: "It‘s a meeting at a lower, liaison level…between representatives of Jackson and Yugoslav generals." The contacts were scheduled to resume at 1100 GMT, Shea said. Jackson remained in Macedonia and was prepared to meet the Yugoslav high command again. The talks, described by NATO as a handover of detailed pullout instructions to the Serbs, broke down in the early hours of Monday over what Shea said was a Serb "attempt to negotiate non-negotiable conditions". Shea said Yugoslav proposals had failed to meet NATO‘s demands for a safe return of ethnic Albanian refugees, the protection of the people of Kosovo and the withdrawal of Serb forces from Kosovo. There had been no movement by the Yugoslav military towards implementing the peace plan drawn up by Russian and European Union envoys and agreed by Yugoslav President Slobodan Milosevic, Shea said. NATO air strikes were continuing, with the air raids against Yugoslavia accelerating towards their prior intensity on Monday after Serbia‘s failure to start a military withdrawal from Kosovo. Alliance aircraft hit tanks, armoured personnel carriers, mortar positions and other vehicles in Kosovo in the past 24 hours but spared infrastructure targets in Serbia. NATO sources said these could be back on the list soon. NATO said it had flown 142 strike sorties on Sunday and early on Monday as Jackson was wrangling with Serbian military officials over their objections to the allies‘ pullout instructions and plan for a NATO peacekeeping force. NATO ambassadors were meeting at alliance headquarters in Brussels to discuss the Serbian stance.

SKOPJE - Grenades were thrown or fired from Serbia into a Macedonian border village early on Monday damaging property but causing no injuries, residents and police said. The incident occured at the village of Jazince, on the border with Kosovo, where ethnic Albanians have been crossing in recent days.

BELGRADE - Air raid sirens sounded across Serbia early on Monday and heavy NATO bombing was reported in Kosovo after talks between NATO and Yugoslav commanders stalled. The Yugoslav news agency Tanjug said dozens of missiles were fired in the Prizren and Pec areas of western Kosovo late on Sunday. The targets included a tea factory and a "picnic area". The state-controlled Yugoslav media rarely acknowledges damage to the military installations NATO says it is aiming at. Belgrade residents said air raid sirens sounded across the city at 1:20 a.m. on Monday and some anti-aircraft fire was heard. Sirens also sounded in other major towns acrosss Serbia and explosions were heard from Mount Rudnik in central Serbia.