Kosovo officials say special police units have withdrawn from two border posts in an ethnic-Serb enclave after a day of violent confrontations with Serb protesters.

The Kosovo special police officer launched an operation late Monday to seize control of the Brnjak and Jarinje crossings on the border with Serbia, but minority Serbs tried to block their progress. One Kosovo policeman was killed in fighting between the two sides Tuesday, while several other people were wounded, including civilians.

The Associated Press quotes a NATO official as saying the commander of the alliance's Kosovo peacekeeping force mediated an agreement to calm the situation in the border areas. Under that agreement, the crossings would be run by border and customs officials from Kosovo's ethnic Albanian and Serb communities.

Kosovo's ethnic-Albanian government had complained Serb police who previously ran the contested border posts were ignoring its orders to block imports from neighboring Serbia.

Serbs who dominate northern Kosovo have refused to recognize the authority of the country's ethnic-Albanian government since it seceded from Serbia in 2008. Belgrade also rejects that secession.

Kosovo Prime Minister Hashim Thaci said Tuesday the special police operation was necessary to close what he called a legal “black hole” in the Serb enclave. But Serbian President Boris Tadic accused Pristina of trying to take over ethnic-Serb areas, and called the move completely unacceptable.

The European Union criticized Kosovo for not coordinating the border post operation with the international community. E.U.-mediated talks between Kosovo and Serbia have made little progress in reconciling the two sides.