A charred body has been found in the US embassy in Belgrade, ransacked by rioters late on February 21 2008, in retaliation of US recognising Kosovo's secession from Serbia.

Police didn't identify the dead person, which the State Department said wasn't a US citizen, Bloomberg reported. Hundreds of people stormed the US embassy, which had a several security personnel there at the time, but was not protected by the police.

One protester ripped the US flag off its pole and briefly put up a Serbian flag in its place, while others jumped on the embassy balcony, holding up a Serbian flag, before riot police dispersed the crowd using teargas, Reuters said.

More than 150 people were injured in the incident, of them 113 taken to hospital, including 35 policemen, Serbian daily Politika said. The embassies of Britain, Canada and Croatia were also targeted.

The US State Department condemned the attack and asked Serbia's government to protect the embassy. The UN Security Council council also came out to voice its disapproval, passing an unanimous statement to that end, Reuters reported.

Serbia said it regretted what it called acts of isolated vandals who did not represent a nation which, while bitter at Kosovo's declaration of independence on Sunday, did not want further violence. "The acts that were committed are absolutely unacceptable, absolutely regrettable," foreign minister Vuk Jeremic said, as quoted by Reuters.

The rioters attacked the embassies around the same time that at least 200,000 people attended a religious vigil in the Saint Sava cathedral in Belgrade, following a government-organised rally. The march, the biggest in Belgrade since the protests that brought down Slobodan Milosevic, had overwhelmed the police, Jeremic said.