A police officer has been killed and another injured in a shooting in area of Kosovo near Serbia.
Kosovo Prime Minister Albin Kurti said the attack in the northern village of Banjska in Leposavic involved "professionals" using heavy weapons. The incident is ongoing, Mr Kurti said.
Tensions have run high in Kosovo, after violent clashes followed a disputed local election in May.
EU-mediated political talks designed to stabilise the situation have stalled.
Kosovo declared independence in 2008 but Serbia - along with Belgrade's key allies China and Russia - does not recognise it.
Many Serbs consider it the birthplace of their nation. But of the 1.8 million people living in Kosovo, 92% are Albanian and only 6% Serbian.
Sunday's shooting happened at about 03:00 (01:00 GMT), after police said they arrived in Banjska, near the border with Serbia, where a blockade had been reported.
Officers were attacked from several different positions with "an arsenal of firearms, including hand grenades and shoulder-fired missiles", they said in a statement.