( AP )- Serbs protesting Kosovo's independence for a fifth straight day Friday attacked U.N. police guarding a key bridge in northern Kosovo with stones, glass bottles and firecrackers.
The U.S. ambassador to Serbia, meanwhile, demanded that the government guarantee the safety of foreign diplomatic missions and their personnel in the capital after an attack Thursday on the U.S. compound.
Serb protesters set fire to the embassy, angered by U.S. recognition of Kosovo's declaration of independence over the weekend.
"We are demanding from the Serbian government that they condemn the violence that took place yesterday and guarantee that it will not be repeated," Ambassador Cameron Munter said in an interview.
The State Department ordered nonessential diplomats and the families of all American personnel at the U.S. Embassy in Belgrade to leave Serbia.
Serbian President Boris Tadic called an emergency meeting of the national security council and said the rioting that engulfed the capital must "never happen again."
"I most sharply condemn the violence, looting and arson," Tadic said in a statement. "There is no excuse for the violence. Nobody can justify what happened yesterday."
Kosovo's ethnic Albanian leaders declared independence from Serbia on Sunday. The province, which is 90 percent ethnic Albanian, has not been under Serbia's control since 1999, when NATO launched airstrikes to halt a Serbian crackdown on ethnic Albanian separatists. A U.N. mission has governed Kosovo since.
In Serb-dominated northern Kosovo, demonstrators waved Serbian flags and chanted "Kosovo is ours!" Police tried to keep protesters off the Kosovska Mitrovica bridge over the Ibar River. The bridge, which divides Kosovo Serbs from ethnic Albanians, has long been a flashpoint of tensions in Kosovo's restive north.
"Kosovo is Serbia and we will never surrender despite blackmail by the European Union," Dragan Deletic, a Serbian government official, told the crowd which responded by chanting "Kosovo is Serbia."
Several EU countries, including Britain, Germany, France and Italy, have recognized Kosovo.
Tensions among demonstrators was higher than usual Friday because French NATO peacekeepers on Kosovo's border refused to allow the passage of several busloads of Serbs who wanted to join the Kosovo Serb rally Friday.
There were fears that Serbian soccer hooligans, the same ones who attacked the U.S. and other embassies in Belgrade on Thursday, were among those on the buses. Some of the hooligans apparently managed to evade the blockade, leading the clashes at the bridge.
On Thursday, nearly 200,000 demonstrated in downtown Belgrade against Kosovo independence. Rioters stormed the U.S. Embassy and set fire to offices and police guardhouses on the sidewalk in front of the building. Firefighters found a charred body inside the U.S. embassy.
Serbian police said more than 150 people were injured in the unrest. Nearly 200 people were arrested and 90 shops ransacked.
The White House strongly criticized the Serbian government, saying the U.S. Embassy in Belgrade "was attacked by thugs" and Serb police did not do enough to stop it. In a conference call with reporters from Air Force One, presidential spokeswoman Dana Perino said the United States had expressed its "concern and displeasure" to the Serbian government.
The riots were the first major outburst of anti-Western sentiment in Serbia since former leader Slobodan Milosevic was ousted in 2000 and replaced by a reformist government.
The tensions have exposed a deep rift within the country's shaky coalition government, raising fears that nationalist anger over Kosovo was strengthening the hard-liners who want to move Serbia away from the European Union and closer to its traditional ally Russia.
Russia's envoy to NATO Dmitry Rogozin said Friday the move to recognize Kosovo was a "strategic mistake" and suggested that Moscow might have to use "brute military force" if the alliance expands its current peacekeeping operation in the territory.
Third-ranking U.S. diplomat Nicholas Burns called on Russia to repudiate the suggestion.
"We strongly advise Russia to be more responsible in its public comments toward Kosovo," Burns said, responding to questions in an online written discussion. " Russia is isolated this week - very few countries are supporting its position."
The EU warned Serbia that the attacks risked harming efforts to bring the Balkan nation closer to the EU.
"These acts of violence lead nowhere and they cannot help anybody," said EU foreign policy chief Javier Solana. He told reporters that negotiations on an agreement designed to prepare Serbia for eventual EU membership would have to wait until things "calm down."
In Kosovo, Prime Minister Hashim Thaci said Friday the violence was reminiscent of Milosevic's bloody crackdown on ethnic Albanian separatists in Kosovo.
"What we saw were terrible things," Thaci told The Associated Press in his first interview since Kosovo declared independence on Sunday. "It was a reaction against a democratic world."
Pro-Western politicians in Serbia accused hard-line nationalists in the government of Prime Minister Vojislav Kostunica of inciting the violence.
Tadic's and Kostunica's parties are united in a coalition government that has ruled Serbia since mid-2007.
But the two differ sharply on how to handle Kosovo's independence, with Tadic saying Belgrade must press on with efforts to join the EU regardless of Kosovo, and Kostunica seeking to drop the bid because most EU countries plan to recognize the province's independence.
Kostunica appealed for an end to the violence.
"This directly damages our ... national interests. All those who support the fake state of Kosovo are rejoicing at the sight of violence in Belgrade," he said. But he made no mention of the damaged embassies.
Police said that in addition to the U.S. and Croatian embassies, the missions of Turkey, Bosnia, Belgium and Canada also were targeted.
Also Friday, the U.S. ambassador to neighboring Bosnia said he had closed the consulate in the northwestern city of Banja Luka a day after protesters burned the U.S. flag and tried to storm the consulate building.
Bosnia consists of two ministates, one run by Bosnian Serbs, the other by Bosniaks and Croats. The Bosnian Serb Parliament has condemned Kosovo's move and said it will consider a referendum to secede from Bosnia if more countries recognize Pristina's government.