Click here for live coverage on the crisis
Click here for map showing refugee movements

Nato says it holds President Slobodan Milosevic responsible for the safety of three United States soldiers captured by Yugoslav forces.

General Wesley Clark, Nato's supreme commander in Europe, said he was "very concerned" about the safety of the soldiers. He said they had been "abducted" by the Serbs in neighbouring Macedonia.

Serbian television, which broadcast footage of the three men, said they had been captured on Yugoslav territory.

The three US soldiers are to face a Yugoslav military court on Friday, the official news agency Tanjug reported.

US Defence Secretary William Cohen said the US would "spare no effort" in seeking their release.

The BBC's Bridget Kendall : 'Exactly what NATO had been dreading'

News of the capture came as Nato stepped up its air assault on Yugoslavia, destroying an important bridge.

Tens of thousands of refugees continue to leave Kosovo for neighbouring territories.

Milosevic meets Albanian leader

Serbian television has shown footage of a meeting between President Milosevic and the Kosovo Albanian leader, Ibrahim Rugova.

The television commentary said the two men had agreed on the need to achieve a political settlement to the conflict.

Meanwhile, Russian President Boris Yeltsin has called for a meeting of foreign and defence ministers from the G8 group of industrial countries, to seek a solution to the Kosovo crisis.

Captives named

The US soldiers captured on Wednesday have been identified as:

• Staff Sgt Andrew A Ramirez, 24, from Los Angeles, California
• Staff Sgt Christopher J Stone, 25, from Smiths Creek, Michigan (about 50 miles north-east of Detroit)
• Specialist Steven M Gonzales, 24, from Huntsville, Texas

Yugoslav Deputy Prime Minister Vuk Draskovic: We won't lay a finger on the soldiers

The three would "face justice according to normal democratic procedures", Yugoslav Deputy Prime Minister Vuk Draskovic told the BBC.

He described the men as "aggressors", but gave assurances they would be treated in compliance with the Geneva Convention on prisoners-of-war.

The three had "put up resistance" during their capture, the report said.

The TV images show some signs of physical injury.

The missing soldiers had reported coming under small arms fire and being surrounded while carrying out a daytime reconnaissance mission in the Kumanovo area of Macedonia, Nato said.

They had radioed for help between 1430 (1230 GMT) and 1500 local time, the Pentagon said, but their colleagues had failed to locate them.

Accidentally in Yugoslavia?

The soldiers were one of several army units guarding the Yugoslav-Macedonia border during Nato's air attacks against Yugoslavia.

But a BBC Correspondent in the region, Paul Wood, says parts of the border are not clearly marked, and it is possible that the three men strayed into Yugoslavia without knowing it.

Our Defence Correspondent, Mark Laity, says the capture is a propaganda coup for the Serbs, and an embarrassment for Nato.

He says questions are bound to be asked about what the men's vehicle was doing out of sight of other troops, so close to one of the most dangerous borders in Europe.

Important bridge bombed

The BBC's Jonathan Charles: "Bridge was an important transit route"

A road bridge over the Danube has become the first major civilian target to be hit by Nato.

The bridge in the town of Novi Sad was an important transport link between Belgrade and northern Serbia.

A spokesman said Nato's Secretary-General Javier Solana had told the military to "extend the range and tempo of operations to maximise the effectiveness of the campaign".

The Yugoslav news agency, Tanjug, also reported several explosions in Kosovo's capital, Pristina, but said Belgrade was quiet.

Refugee exodus

Kosovo refugees are still massing at Macedonia's border

Thousands of refugees are continuing to flee Kosovo amid reports that civilians in Kosovo could face starvation within 10 days.

The head of the United Nations World Food Programme, Catherine Bertini, said her organisation had no way of reaching them, and air drops had been rejected as too dangerous.

United Nations officials said 11,000 had crossed the border into Albania within 24 hours, bringing the total influx there to nearly 100,000.

US President Bill Clinton has authorised $50m in emergency relief.

Several European countries have also pledged aid.

Foreign ministers from several central European and Balkan countries are due to meet in Germany to discuss co-ordinating assistance to the refugees.