Serbia's hard-line nationalist leaders have claimed the US is "the main culprit" in the violence that has broken out since Kosovodeclared independence.
Several thousand Serbs chanting "Kosovo is Serbia!" and "Russia, Vladimir Putin!" protested peacefully in the ethnically divided town of Kosovska Mitrovica, the sixth day of demonstrations against Kosovo's break with Serbia. Russia backs Serbia's fierce resistance to Kosovo's secession.
On Thursday night, protesters in the Serbian capital Belgrade set fire to the US embassy, angered by Washington's recognition of Kosovo. The US and the European Union responded by demanding Serbia protect foreign embassies.
"The United States is the main culprit ... for all those violent acts," Serbia's Minister for Kosovo Slobodan Samardzic said in Belgrade.
Other Serbian leaders have called for calm after the riots. But an aide to hard-line Serbian Prime Minister Vojislav Kostunica said any future violence also will be blamed on the US.
"If the United States sticks to its present position that the fake state of Kosovo exists ... all responsibility in the future will be on the United States," Kostunica adviser Branislav Ristivojevic said in a statement.
The comments were an indication that Serbia is drifting further from the West and more toward ally Russia.
The vast majority of Kosovo's population is ethnic Albanian and Serbs represent about 10 per cent of the region's 2 million people.
Kosovo had formally remained a part of Serbia even though it has been administered by the U.N. and NATO since 1999, when NATO airstrikes ended former Yugoslav leader Slobodan Milosevic's crackdown on ethnic Albanian separatists, which killed 10,000 people.