NATO commanders today presented Yugoslav military officers with detailed plans for the withdrawal of Serb-led Yugoslav forces from Kosovo, but the five-hour meeting near Macedonia's border with the Serbian province ended inconclusively and the two sides agreed to resume talks on Sunday.

Details of the talks, which were delayed three hours because the Yugoslav officers arrived late, were closely held. But allied officials were publicly upbeat afterward.

"We had a constructive day of very positive talks," said British Lt. Col. Robin Clifford, the spokesman for Lt. Gen. Mike Jackson, commander of the Allied Rapid Reaction Corps deployed in Macedonia and the lead NATO representative at the meeting. The talks were held at an ethnic Albanian restaurant overlooking the road traveled by more than 200,000 refugees who have fled Kosovo since March.

Although one official who was present at the discussions said "the situation is fragile," sources attributed the difficulties primarily to the fact that the Yugoslav officers were not given complete authority by the Serb-led Yugoslav government in Belgrade to approve central aspects of the deal. One said problems arose because the Yugoslav officers "did not have the authority to say yes to certain points," even though they left the meeting twice to drive to a Yugoslav border station and call Belgrade.

NATO and Pentagon officials reported no sign of the start of a withdrawal of Yugoslav forces from Kosovo, and said allied war planes continued operations today over Serbia and its embattled southern province. Serbia is Yugoslavia's dominant republic.

Yugoslav media reported today that NATO warplanes had struck targets overnight near the western Kosovo town of Decani and the southern city of Prizren, 25 miles west of Blace. Air raid sirens also sounded throughout Serbia proper, including Belgrade.

Pentagon officials reported continued fighting between Yugoslav forces and Kosovo Liberation Army rebels around Mount Pastrik along the Kosovo-Albanian border. Late tonight, Yugoslav forces shelled the northern Albanian border town of Krume, which is crowded with refugees, the Associated Press reported.

The shelling sent relief workers and residents scurrying into cellars, according to international monitors. One person was killed and several injured, according to officials from the Organization for Security and Cooperation in Europe.

U.S. Air Force pilots flying from Aviano Air Base in northern Italy -- one of the largest operational centers of the 74-day air campaign -- said the rules of engagement were abruptly tightened today. The pilots said they are now permitted to fire bombs or missiles only if Yugoslavian troops or Serbian police forces are attacking civilians, Kosovo Liberation Army rebels or NATO aircraft, or if they appear to be massing for such an attack.

Pentagon officials have said a suspension of bombing would follow shortly after the start of a withdrawal of Yugoslav forces from Kosovo can be confirmed.

Air Force officials said all NATO planes except one launched from Aviano returned to the base today without dropping bombs or missiles. Officials said one pilot reportedly attacked a Yugoslav artillery position.

"We're out there to still show force," said Lt. Col. Steve Schrader, operations officer of the U.S. Air Force 510th Fighter Squadron. "If we see blatant noncompliance, we're going to stop them. Today we didn't see anything."

Schrader said he spotted a large number of buses congregated in one Kosovo town and speculated they were being readied to move troops, but said he had no concrete evidence as to whether soldiers had been loaded onto the buses.

After today's meeting in Macedonia -- the first between NATO and Yugoslav military officials since shortly before NATO airstrikes began -- Clifford said the two sides spent the afternoon on a "word-by-word, line-by-line" discussion of a technical agreement described as having six pages and spelling out such matters as the timing and routes of the required Yugoslav troop withdrawal.

The Yugoslav side was represented by Col. Gen. Blagoje Kovacevic, assistant chief of staff for the Yugoslav Army, and Gen. Obrad Stevanovic, an assistant Serbian interior minister, whose ministry controls Serbia's police forces. That decision appeared to reflect the fact that the bosses of the two men, Serbian Interior Minister Vlajko Stojuljkovic and Yugoslav Army chief of staff Col. Gen. Dragoljub Ojdanic, have been indicted by the international tribunal in The Hague for alleged war crimes in Kosovo.

The remainder of the Yugoslav delegation was filled out by army, Interior Ministry, and Foreign Ministry officials, while the NATO delegation included Jackson and three other generals from Britain, France, and the United States, as well as an observer from the U.S. Joint Chiefs of Staff. They sat on opposite sides of a table at the Europe 93 snack bar in a hot, dark and drab, two-story building with five lace curtains and one green one.

The Yugoslav delegation came and went in four dark sedans, escorted by a white all-terrain vehicle filled with troops, and as they passed through the Macedonian border station, they came within sight of the Blace camp, where as many as 10,000 ethnic Albanians have been housed in recent weeks, although only 4,100 were present today.

As they met, NATO spokesman Jamie Shea said in Brussels that the document presented by Jackson contained "crystal clear" plans for the rapid pullout of regular army and Serbian Interior Ministry troops, border police, armed civilians, national guard, reserve forces, anti-terrorist forces and any other group designated by Jackson. It also makes clear that NATO "will not tolerate any hindrance" of its own speedy deployment of allied forces into the province as part of an international peacekeeping mission.

NATO officials had said the session would not become a negotiation, but that term was used by two officials who were present when they described the exchange. They declined to provide details of principal sticking points, but one said the issues were "not necessarily critical elements."

Shea also made the clearest pledge to date that the NATO forces to be deployed inside Kosovo within a day or two after the agreement is finalized will be able to roam freely throughout the Connecticut-size province. "It is our intention to have soldiers of the international security force, including of course many NATO soldiers, in every village and on every street corner," Shea said. "We are not talking about differentiated zones" under separate military commands.

The point has not been agreed upon with Russia, which also plans to contribute troops to the peacekeeping mission.

Meanwhile in Washington, U.S. Defense Secretary William S. Cohen expressed concern today about avoiding any "security void" between the departure of Yugoslav forces and the entry of NATO peacekeepers, in part to keep Kosovo Liberation Army rebels from attacking or seizing territory in the province. "That's why it's important we move in quickly, with significant force, so they will see there's no enemy there for them to attack," Cohen said.

Pentagon officials said a contingent of 2,200 Marines, who would be among the first allied troops into Kosovo, was due to reach the Greek port of Thessaloniki by late Sunday. They would then proceed overland to Skopje, Macedonia, on Monday.

"The exact time that they go in, or any NATO force goes in, depends on the Serb forces starting their withdrawal," Bacon said. "My expectation is that the initial troops will enter on the ground and survey the situation. And then, after they have secured landing zones and seen what the situation is, then helicopters would come in."

Besides the military uncertainties, many questions about the humanitarian relief efforts and refugee returns to Kosovo also remain unresolved, according to officials of the U.N. High Commissioner for Refugees. The group is sending a team to Belgrade on Monday or Tuesday to meet with Yugoslav officials.

Correspondent Molly Moore at Aviano Air Base, Italy, and staff writer Bradley Graham in Washington contributed to this report.

CAPTION: Yugoslav delegates, including Col. Gen. Blagoje Kovacevic, front, and Gen. Obrad Stevanovic, rear in jacket, leave meeting with NATO in Macedonia.

CAPTION: Yugoslav President Slobodan Milosevic, left, speaks during a meeting Thursday with Russian special envoy Viktor Chernomyrdin, center, on ending the conflict in the Balkans over the Serbian province of Kosovo.