A European Union police officer from Lithuania has been shot dead in Kosovo, the first casualty since the EU took over security in 2008.
The Eulex mission condemned the “act of cowardly violence” and said a murder investigation had been launched.
It said two vehicles carrying six staff members had come under fire while on patrol in the Mitrovica area of northern Kosovo.
The town of Mitrovica is split between ethnic Serbs and Kosovo Albanians.
“At approximately 07:30 local time (05:30 GMT), two vehicles carrying six staff members came under fire in the vicinity of Zvecan town,” Eulex said.
“No effort will be spared in bringing the perpetrator to justice.”
A spokeswoman for the EU mission, Irina Gudeljevic, told the BBC it was the first time a member of the Eulex force had been killed.
Mission head Bernd Borchardt said in a statement that the man who died was a customs officer with a wife and family. “I am shocked at the callous nature of the murder,” he said.
EU foreign affairs chief Catherine Ashton said she was deeply saddened by the death.
The attack took place on the road between Mitrovica – 36km (22 miles) from Kosovo’s self-declared capital, Pristina – and the town of Jarinje, Serbian news agency Tanjug reported.
Mitrovica hospital sources told Tanjug the victim had been admitted in an unconscious state with bullet wounds at about 08:00 (06:00 GMT). Doctors tried to revive him for an hour, but without success.
Vehicles from Eulex and local Kosovo police were deployed around the hospital. Police also restricted access to the area of the shooting.
Kosovo declared independence from Serbia in 2008, and the Eulex mission took control of police, justice and customs services.
Tensions have since persisted in northern Kosovo, which has a sizeable Serbian population.
However, Kosovo and Serbia signed an EU-brokered deal on normalising relations in April this year, providing considerable autonomy to Serb-majority areas.
Municipal elections are scheduled to take place in Kosovo on 3 November.