“At this moment, gunfire with various calibre firearms against our police is still ongoing,” Kurti said in a post on Facebook, describing the incident as terrorist action.

“The attackers are professionals wearing masks and heavily armed.”

Tensions have run high in Kosovo, the former Serbian province, after clashes in May when more than 90 Nato peacekeeping soldiers and some 50 Serb protesters were injured in northern Kosovo.

Ethnic Albanians form more than 90% of the population in Kosovo, with Serbs being the majority only in its northern region where a Serb-majority municipalities association is planned.

EU-sponsored talks on normalising relations between the two former wartime foes stalled last week, with the bloc’s foreign policy chief Josep Borrell blaming Kurti for failing to set up the association of Serb-majority municipalities which would give them more autonomy.