Nato has said the Yugoslav military commanders at the face-to-face meeting in Macedonia are using delaying tactics.

Alliance officials say the talks will be scrapped if the Serbs do not sign a pullout deal by the end of Sunday.

The talks have been suspended while the Yugoslav delegation consults President Slobodan Milosevic. The delegates said they were prepared to work through the night.

Yugoslavia is reported to be insisting that no Nato troops can enter Kosovo until all Serbian forces have left, and that the bombing be suspended at the beginning of the pullout.

The alliance wants to move into Kosovo as soon as any pullout begins. It said it would suspend the air campaign after one day if Yugoslavia proved it was withdrawing.

Ben Brown in Macedonia: The talks may be on the brink of collapse

Nato fears the Serbs are trying to trick them and that once the air raids stop, so too will the withdrawal.

Such a strategy could give President Milosevic both the ceasefire he wants and a continuing military grip on Kosovo.

A BBC correspondent at the talks, Paul Wood, says it would be extremely difficult diplomatically to restart the air campaign.

(Click here to see a map of forces on the ground)

Russia's military attache to Belgrade has arrived at the meeting, and alliance officials are hopeful he may be able to persuade the Serbs to change their stance.

Russia's Balkans envoy Viktor Chernomyrdin has said Russian involvement in any peace-keeping force will be worked out in the next few days. The Russians are traditional Serbian allies.

Earlier, a Nato spokesmen warned that if the talks broke down it was perfectly prepared to intensify its bombardment, which has been reduced over the past three days.

On Saturday night, the state-run news agency Tanjug reported intense missile strikes in Pristina, Pec and Prizren, but no attacks were reported elsewhere in Yugoslavia.

(Click here to see a map of last night's Nato strikes)

Nato has also revealed that even after President Milosevic agreed to the joint Western-Russian peace plan on Thursday, Serb forces perpetrated further outrages in Kosovo.

Over the last two days, there has been mass looting in Prizren and Pristina, and a group of displaced Albanian civilians has been shelled.

Nato spokesman Jamie Shea warned that this was being closely observed and advised Serb forces not to leave what he called "a final calling-card".

Nato impatient

Nato officials have said privately that they have had enough of Serb procrastination at the talks - being held at a Nato base in Kumanovo, about six miles south of the Yugoslav-Macedonian border.

Nato wants the Serbs to agree to withdraw all their forces from Kosovo within seven days via designated routes.

Correspondents say the Yugoslav delegation is arguing that the Serbian military, transport facilities and infrastructure are too weak to enable it to keep to Nato's timetable.

The Serbian sticking points are also reported to include Nato's demand for Yugoslav forces to pull back beyond a 25km buffer zone inside Serbia, which they say is a violation of their sovereignty.

In addition, diplomatic sources said the Serbs were being asked to clear minefields before they leave - a task which the Yugoslav delegation says would take too long.

The Yugoslavs may also be asking for special arrangements in the west of the province, where their troops are still heavily engaged with the Kosovo Liberation Army.

Albanian town bombed

On Saturday, about 300 KLA fighters were reported to have moved up to reinforce their positions on the frontline.

Serbian forces shelled a northern Albanian border town, sending relief workers, locals and refugees fleeing into cellars, international monitors said.

Around 10 shells landed in the town where the KLA has set up a hospital for its fighters, although there were no reported casualties.

In another incident, riot police had to be called to a refugee camp in Macedonia when Kosovo Albanians attacked members of a gypsy family, accusing them of helping the Serbs drive people from their homes.

The refugees eventually dispersed after the US Ambassador to Macedonia, Christopher Hill, intervened, promising that the family would be prosecuted if there was any evidence against them.

• Piecing Kosovo together
• Belgrade looks ahead
• KLA highlights struggle for survival
• Serbs stony silence
• Q & A: What's in the deal
• Full text of the peace document

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