A charred body was found in the US Embassy this evening in Belgrade after protesters smashed their way into the building in anger at Kosovo's independence and set it on fire.
"A charred body was found in the embassy. All US personnel have been accounted for," said a US official, who spoke on condition he was not named. He had no details on the nationality or identity of the body.
Earlier, protesting Serbs set fire to the US embassy in Belgrade in protest at Kosovo's declaration of independence.
Rioters broke into the US Embassy and set fire to an office after a large protest against Kosovo's independence that drew an estimated 150,000 people.
Masked attackers broke into the building, which has been closed this week, and tried to throw furniture from an office. A blaze broke out but firefighters swiftly put out the flames.
Authorities drove armored jeeps down the street and fired tear gas to clear the crowd. The protesters dispersed into side streets where they continued clashing with authorities.
The neighboring Croatian Embassy also was attacked by the same group of protesters.
In Washington, State Department spokesman Sean McCormack said the US ambassador to Serbia was at his home and in contact with US officials.
Serbia has "a responsibility now to devote the adequate resources to ensure that that facility is protected," McCormack said.
The protesters appeared to have been in the Embassy's consular building area, McCormack said. US security officials and Marine guards were in a separate part of the compound, the chancery, but no staff were present at the Embassy, he said.
More than a dozen nations have recognized Kosovo's declaration of independence on Sunday, including the United States, Britain, France and Germany.
But the declaration by Kosovo's ethnic Albanian leadership has been rejected by Serbia's government and the ethnic Serbians who populate northern Kosovo. Russia, China and numerous other nations have also condemned the declaration, saying it sets a precedent that separatist groups around the world will seek to emulate.
Kosovo, which is 90 percent ethnic Albanian, has not been under Belgrade'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, with more than 16,000 NATO troops and KFOR, a multiethnic force, policing the province.
But Serbia - and Kosovo's Serbs, who make up less than 10 per cent of Kosovo's population - refuse to give up Kosovo, a territory considered the ancient cradle of Serbs' state and religion.
Earlier today, police estimated that about 150,000 people had attended a rally in the Serbian capital. The crowd waved Serbian flags and carried signs reading "Stop USA terror." One group set fire to a red-and-black Albanian flag.