Serbian police said Monday a group of armed Kosovo Albanians on Sunday opened fire on the police while illegally chopping woods inside Serbia.
In Kosovo, police confirmed the clash and said at least 6 people were hospitalized.
The incident could fuel tensions amid efforts by Serbia and Kosovo to normalize ties following 1998-99 war. The former foes forged an agreement in April to gradually resolve problems.
Serbia does not recognize the 2008 declaration of independence by its former province, but must improve relations to move closer to European Union membership.