Two Serbs were killed and two wounded on Saturday night when their car was shot at in southern Kosovo, a local political leader and police sources said.

Serbs have been the target of frequent attacks in Kosovo by the ethnic Albanian majority since the end of the 1998-99 war, which led to the withdrawal of Serb forces from the southern Serbian province and the arrival of a U.N. administration.

The four Serb men were fired on from another car shortly after 11 p.m. (2100 GMT) as they drove near the town of Strpce near Kosovo's southern border with Macedonia, town mayor Stanko Rakovljevic told Reuters.

"They were shot at from a Mercedes which had followed them," he said. The Serbs were driving a car with the old "PR licence plates denoting Pristina, rather than the U.N.-imposed "KS" plates used by the ethnic Albanian majority.

A police source confirmed the killings. The condition of the two wounded men was not immediately clear.

The killings are the worst since a Serb teenager was shot dead in June last year in the Serb enclave of Gracanica, for which two ethnic Albanians have been charged.

It comes as a U.N. envoy prepares to submit a report next month on whether Kosovo has made enough progress on democracy and minority rights for negotiations to begin on its "final status".

The 90-percent Albanian majority wants formal independence from Serbia, which Belgrade opposes.

Western powers intervened in the 1999 war with 78 days of NATO bombing to drive out Serb forces accused of killing and expelling thousands of ethnic Albanian civilians.

After the war, an estimated 180,000 Serbs fled a wave of revenge attacks. Some 100,000 stayed, many in isolated enclaves guarded by members of the 17,000 NATO-led peace force.

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