BELGRADE The European Union told Serbia on Friday to protect embassies after attacks over Western support for Kosovo's secession, and suggested such violence could harm its prospects of closer ties with the bloc.
A U.S. embassy spokeswoman said families of diplomats and support staff were being evacuated after rioters stormed the mission in Belgrade and set it on fire on Thursday. The ambassador and core staff would remain.
"We believe that yesterday's attacks on our embassy were conducted by hooligans and thugs," a White House spokesman said in Washington.
"We quite frankly don't believe that this is the face of Serbia. We've also been assured that there will be no repeat".
The U.N. Security Council condemned the "mob attacks" that came after a mass state rally for Kosovo. Serbia blamed the violence on isolated vandals.
A young man was found dead in the U.S. embassy. The British, German, Croatian and Turkish missions were also attacked.
"Things will have to calm down before we can recuperate the climate that would allow for any contact to move on the SAA (Stabilization and Association Agreement)," EU foreign policy chief Javier Solana said.
Brussels hopes to lure Serbs away from nationalism with the relative stability, prosperity and travel freedom that cooperation with the bloc will bring. Its stance is complicated by its commitment to Kosovo's independence -- declared on Sunday and quickly recognized by Washington and many EU states.
Russia, Serbia's ally, said Western states should have anticipated the backlash over Kosovo, seen by Serbs as the nation's heartland but now home to an Albanian majority who have been under U.N. rule since NATO drove out Serb forces in 1999.
"People who advocated a unilateral proclamation of independence for Kosovo should have calculated the consequences," a Russian Foreign Ministry spokesman said.
In the flashpoint city of Mitrovica in north Kosovo, several thousand ethnic Serbs massed to taunt U.N. riot police on the main bridge after a rally against Kosovo's independence.
A Reuters witness said the mostly young crowd was singing patriotic Serbian songs and chanting anti-Albanian slogans. Some lobbed firecrackers towards the police who were blocking the way to the bridge's southern end, in the Albanian part of the city.
Rallies were also scheduled in Serbia's southern city of Nis and Montenegro's capital Podgorica.
Some 250,000 people, according to city authorities, attended Thursday's peaceful official rally in Belgrade, listening to speeches and songs in a melancholy atmosphere. Serbia's Interior Ministry put the number at half a million.
But several hundred young male rioters split off, smashed their way into the U.S. embassy and set fire to part of the building, the second time in a week that it had been attacked.
A crowd of about 1,000 cheered "Serbia, Serbia" as one ripped the Stars and Stripes off its pole and others jumped up and down on a balcony, holding a Serbian flag.
Some 130 people were injured in street clashes, including 50 police and some journalists, and almost 200 were arrested. European and U.S. leaders criticized police for a slow reaction.
Prime Minister Vojislav Kostunica, whose fiery anti-Western rhetoric has been at the forefront of Serbia's diplomatic battle to keep Kosovo, said the peaceful rally "was magnificent and showed what the people of Serbia thought about Kosovo".
In a statement to state news agency Tanjug, he condemned the violence, saying it "directly inflicts damage to our fight" to protect national interests.
Liberal commentators have attacked him for stoking up tension in the hope that the West would back off from supporting Kosovo so as not to risk a nationalist backlash in Serbia.
"This was a disgrace, it was hooliganism of the worst kind," said Miroslav Markovic, walking his dog past looted, broken kiosks near Belgrade's train station. "The government should have been prepared and not have encouraged these people."
(Additional reporting by Matt Robinson in Mitrovica, Dusko Mihailovic in Podgorica and Gordana Filipovic in Belgrade; Editing by Richard Meares)