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Three United States soldiers have been captured by Serbian troops.

A US military spokesman confirmed the capture, after Serbian television broadcast footage of the three men.

The three soldiers went missing in the Former Yugoslav Republic of Macedonia, close to the border with Serbia.

The TV report, quoting the Yugoslav army, said the men had been captured on Yugoslav territory.

Nato says the soldiers were involved in a routine patrol along the Macedonia-Yugoslavia border.

Serbian TV gave the names of the three men, transliterated into Cyrillic, as Stephen Gonzales, Andrew Ramirez and James Stone.

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

The TV images show some signs of physical injury.

Vuk Draskovic, Yugoslav Deputy Prime Minister: "Nothing wrong could happen to the captives"

The soldiers will "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 political prisoners.

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 says.

Alliance officials have not said who surrounded the soldiers, but Pentagon spokesman Colonel Richard Bridges said the trio could have been abducted by Serb army, paramilitary units or special police forces.

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

Nick Childs reports: "This is public relations, rather than a military set back"

Urgent radio cries for help came between 1430 (1230 GMT) and 1500 local time, according to the Pentagon. When other reconnaissance teams in the area, from the Army's 1st Infantry Division, failed to locate their colleagues, they radioed their commanders for help, the Pentagon said.

BBC Defence Correspondent Mark Laity says the reported capture is a propoganda 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.

Strikes 'increasingly painful'

Reports of the capure follow an intensified air assault against Yugoslavia by the Allied forces on Wednesday night.

Katty Kay: The latest reports are bound to increase concerns for US soldiers' safety

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".

Yugoslavia's state-run Tanjug news agency reported that Allied forces had destroyed a bridge over the Danube River at Novi Sad on the eighth night of their bombing campaign.

The BBC's Emma Jones : 'NATO is keen to stress they are getting results'

The bridge was an important transport route between Belgrade and northern Serbia.

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

John Simpson reports from Belgrade: "We're talking about a propaganda war"

State-run television broadcast footage of the destroyed bridge, which links the northern town of Novi Sad with Petrovaradin.

Correspondents say that it is the first reported attack against Yugoslav infrastructure.

The UK was among those warning that Nato's attacks would become "increasingly painful". Defence Secretary George Robertson warned President Milosevic: "We are not going away."

Serb military leader Arkan: Will not give in to Nato

Mr Robertson said that those responsible for war crimes against Kosovo Albanians would be hunted down and brought to justice, adding: "We know who they are and where they live." Refugees 'face starvation'

However, the growing refugee crisis has lent Nato's mission greater urgency, with 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.

Kosovo refugees are still massing at Macedonia's border

Thousands of refugees from the province are continuing to pour across its frontiers into neighbouring countries - already struggling to cope with the tide of refugees who have fled their homes since Nato launched its bombing campaign.

The UN High Commissioner for Refugees said on Wednesday that at least 118,000 Kosovo Albanians had fled to Albania, Macedonia and Montenegro.

But the Yugoslav Government was insisting that Nato air strikes had provoked the mass exodus.

Its UN representative, Vladislav Jovanovic, told the Associated Press that President Milosevic had issued an invitation on Tuesday to all displaced Kosovo Albanians to return to Yugoslavia.