Until 1999, this was an unmarked Serbian provincial border. Until last week, it was a U.N.-supervised crossing. Now it is an international frontier, at least for states recognising Kosovo.
Serbia has said it will not let a new frontier separate Serb from Serb. Its ally Russia has no troops in the Balkans but has promised to oppose Kosovo's "illegitimate" independence.
FLAG RUMOUR
A Serb journalist told the BBC the attacks were triggered by rumours Kosovo's new flag was about to be raised at the posts.
It was not clear if U.N. police and Kosovo Customs planned to return to restore the border point on Wednesday.
A KFOR spokesman said the attacks seemed "well organised, according to the number of buses we saw moving to the north".
Serbia, which hopes to move closer to the EU, recalled its ambassadors to Washington, Paris and some other countries in protest at recognition of Kosovo announced on Monday by the United States and EU powers but insisted it would not cut ties.
In Vienna, Serbian Foreign Minister Vuk Jeremic said Belgrade would "fight tooth and nail" to oppose Kosovo, using all means short of military force, but its options are limited.
Current plans include a mass Belgrade protest on Thursday.
Serbs dominate the northwest corner of Kosovo, where the United Nations failed to establish its authority. It took control of the province in 1999 after NATO bombed Serbia to force an end to repression and compel its troops to leave.
Serbian state institutions are well entrenched in the enclave, now with explicit Russian diplomatic backing.
"We'll strongly warn against any attempts at repressive measures should Serbs in Kosovo decide not to comply with this unilateral proclamation of independence," Russia's U.N. ambassador Vitaly Churkin said on Sunday.
Jeremic urged KFOR to remain even-handed and protect Serbs in Kosovo, where those in isolated southern enclaves are particularly vulnerable.
U.S. President George W. Bush welcomed independence.
"History will prove this to be a correct move, to bring peace to the Balkans," he said. "We will work with the leaders of Kosovo to carry out a smooth and peaceful transition."
