Dozens of people were on the narrow road bridge over the river when the first pilot dropped his missile.
Divers were searching for survivors, said the Yugoslav news agency Tanjug, adding that the strike had killed at least 11 but that the number could be much higher. They said more than 40 peoplehad been injured, including five in critical condition.
It was 12.53 when the first plane hit the bridge at one end. A second plane came back 15 minutes later and hit the bridge once more. But by that time people had rushed from the nearby village to help victims from the first attack only to come under attack themselves.
The first reporters on the scene spoke of "pools of blood" lying by the bridge. They said it was obvious that people had been blown to pieces.
Footage shown on Yugoslavia's state television showed the destroyed span, its metal construction tumbled into the river. A shoe was lying nearby. Glass windows of nearby riverside cottages were smashed.
There was no immediate comment from Nato on the report. But although it could not be independently verified, there was no serious doubt about who was responsible. The Serb authorities only buss in Western reporters when they are sure they have an "atrocity" on their hands.
And Nato has acknowledged killing civilians several times in the course of the air strikes, now in their third month, though it insists all such casualties are unintentional.
Instead, Nato's comments yesterday centred on attempts to force the Yugoslav leader Slobodan Milosevic to agree to a Kosovo peace plan that was acceptable to the alliance. The alliance spokesman Jamie Shea said the Yugoslav President was slowly moving "from the position of almost total defiance of the international community" but was far still far away from accepting "without reservation, without negotiation," Nato's conditions for ending the air campaign.
The deaths from Nato attack on the bridge brought the civilian death toll to 19 due to weekend Nato air strikes.
In Belgrade, a man was killed when his car veered off a bridge and plunged into the Sava River yesterday. Officials said he apparently was speeding across the span for fear it might be bombed while he was on it. A media report also said a 60-year-old pensioner was killed and 30 people injured, including his wife, during an airstrike near Vranje in southern Serbia.
Airstrikes in Kosovo accounted for the other six reported civilian casualties.
Although the reported error will intensify pressure on the Western alliance to reconsider the air campaign, Nato's military commander yesterday ejected as "a bad idea" the suggestion that a bombing pause might persuade Belgrade to accept alliance conditions for an end to the nine-week air war against Yugoslavia.
"I don't think it's either a bombing pause or diplomacy. I think it's the bombing that's impelling the diplomacy," General Wesley Clark, Nato's supreme commander, told CNN in an interview.
Some observers believe that a Nato bombing pause now could give the Yugoslav President the room he needs to strike a deal with the international community. But the general disagreed.
"It would give them a chance to reconstitute and refit their forces. It would raise the risk to our Nato pilots when we resume operations over Kosovo. So, from a military perspective it's a bad idea," he said.
Yugoslavia's Tanjug news agency reported on Friday that Belgrade accepted the "general principles" set out by the Group of Eight - the G7 major industrialised countries plus Russia - as a basis for bringing peace to Serbia's Kosovo province.
"The mere fact [Milosevic] is making such an offer does demonstrate that the pressure is telling on him," the Foreign Secretary Robin Cook told reporters after meeting Kosovo Liberation Army leader Hashim Thaqi in London.
"We must make sure we keep up the pressure until we get a settlement that meets our full objectives. He needs to go beyond acceptance of general principles and put real substance into the proposals before we know he is serious."
Mr Thaqi said Nato's air campaign was seriously damaging the Yugoslav army's capabilities and morale.
Nato pilots flying combat missions over Yugoslavia have described the landscape in Kosovo as bleak and deserted, and spoke of seeing burning villages, Nato spokesman Jamie Shea said..
"One [pilot] told me how at night, flying over Kosovo, he could see lots of red dots representing houses and villages that were burning," he said after speaking with the pilots in Italy at the weekend.
"Another spoke to me of the deserted landscape in which virtually nothing moved. The roads were empty. No farmers, no activity in the fields. As if the population, like troglodytes, had gone into hiding in caves and deserted houses."
Mr Shea said a third pilot had witnessed Yugoslav special police torching houses in the western city of Djakovica.
While hundreds of thousands of ethnic Albanians have left Kosovo, aid organisations believe about 600,000 are still in the southern Serb province. They say many of the remaining Kosovo population are homeless and hiding in towns or in the mountains.
Residents of Kosovo reporters by telephone at the weekend that Serb policemen were combing residential areas of the province, seeking remaining Albanians to issue them new registration cards controlling their movements.Reuse content