Serb police attacked ethnic Albanians in Serbia's restive Kosovo province Thursday, an Albanian leader said. His aides called it a massacre, with houses burning and residents fleeing into the forest.

Serb police said they moved in on the Drenica region after an early morning attack on a police station that injured two policemen. The region was the scene of another retaliatory Serb attack last weekend that killed at least 25 ethnic Albanians.A spokesman for Kosovo's Albanian leader, Ibrahim Rugova, called the situation "dramatic," with houses burning and "massacres being carried out."

Serbia was sending heavy reinforcements for its police forces in the region, according to reports by both Belgrade independent radio station B-92 and the ethnic Albanian-controlled Kosovo Information Center.

The reports could not immediately be confirmed. There was no immediate word on how many people may have been killed.

Serb authorities contend the ethnic Albanians' accounts are exaggerated. They say they are responding to provocations backed by the clandestine Kosovo Liberation Army, which advocates an armed struggle for independence for Kosovo - where ethnic Albanians outnumber Serbs 9-to-1.

"Today's attack proves the unprecedented brutality of the Belgrade regime," said Rugova's spokesman, Mustafa Xhemaje.

Another spokesman, Enver Maloku, cited "great panic among the population," with women and children being evacuated on tractors and fleeing the region while the men escaped to nearby forests.