PRISTINA, Serbia-Montenegro - NATO-led forces surrounded a key Kosovo town as the alliance moved to separate ethnic Albanians and Serbs and prevent a resurgence of attacks that killed 28 and wounded 600 in the worst spasm of violence in five years.

Thousands of fresh NATO forces took up positions throughout the U.N.-run province, days after every major city here was hit by rioting, arson and gunfights. It took days for the extent of the bloodletting to become clear - a symbol of the breakdown of law and order.

The commander of NATO forces in southern Europe, Adm. Gregory Johnson, declared that the violence "essentially amounts to ethnic cleansing." He demanded an end to "mob violence, thuggery and criminal activity."

The rioting declined, but mobs of ethnic Albanians looted several villages and apartments abandoned by Serb civilians. Some 110 homes and at least 16 Serb Orthodox churches were destroyed by arson.

Authorities reduced the number of dead from 31 to 28 and tallied 600 people wounded after picking through the charred rubble and the ruins of homes throughout the province.

The continuing violence underscored the divisions that have polarized Kosovo's mostly Muslim ethnic Albanians, who want independence from Serbia, and Orthodox Christian Serbs, a minority in Kosovo who consider the province their ancient homeland.

Trying to get a grip on the situation, NATO bolstered its 18,500-member peacekeeping force with reinforcements from Austria, Britain, Denmark, Germany, France, Italy and the United States, urging restraint in Kosovo and elsewhere in the turbulent region.

The alliance also showed new resolve in cracking down on lawbreakers.

Peacekeepers ringed the divided city of Kosovska Mitrovica, where the violence began on Wednesday, and hunted down and killed a sharpshooter who had fired at French forces from one of three high-rise apartment buildings inhabited by ethnic Albanians there, said U.S. Lt. Col. Jim Moran, a spokesman for NATO.