One police officer was killed and another wounded early Sunday near the Serbian border by heavily armed attackers, police said in a statement.
The two officers were patrolling near a road that was blocked when "the police unit was attacked from different positions with heavy weapons, including grenades," according to the statement.
Kosovo Prime Minister Albin Kurti immediately criticized an attack "carried out by professionals, masked and equipped with heavy weapons. We condemn this criminal and terrorist attack," he wrote on social media. "Organized crime, with financial and logistical support from Belgrade officials, is attacking our country."
Northern Kosovo is the scene of recurring unrest, and tension there suddenly increased in May, when Kosovo authorities decided to appoint Albanian mayors in four Serb-majority municipalities. More than 30 soldiers from KFOR, the NATO-led force in Kosovo, were injured in late May in clashes with Serbian protesters.
Serbia refuses to recognize the independence of its former province, whose population of 1.8 million, mostly of Albanian origin, includes a Serbian community of about 120,000 people, living mainly in northern Kosovo.
Since a conflict that left 13,000 dead, mostly Kosovar Albanians, relations between the two former enemies have gone from crisis to crisis.
