A Serb teenager has been killed in a drive-by shooting in the village of Gracanica in Kosovo, triggering fears of new ethnic clashes in the province.
There are fears Kosovo could again spiral into anarchy
Police arrested two armed suspects,
both ethnic Albanians, soon after the attack in the nearby town of Pristina.
Sixteen-year-old Dimitrije Popovic was shot dead at an outdoor fast food stall in the early hours of Saturday.
A similar shooting, blamed on ethnic Albanians, led to a wave of violence in March that left 19 people dead.
Police moved fast to stop a fresh spiral into anarchy, setting up checkpoints in the area and sealing off all roads to Gracanica.
Patrols have also been stepped up, with local police being backed up by Nato-led peacekeepers, who have been in the province under a UN mandate since 1999.
Kosovo's leading Albanian politicians have also condemned the killing and called for restraint.
"I call on all citizens to remain calm," said Prime Minister Bajram Rexhepi, adding that the killers will be brought to book.
The BBC's Matt Prodger in Belgrade says the killing comes at a time of high tension in Kosovo, with many fearing that further outbreaks of violence in the province are imminent.
The rioting in March followed a similar shooting of a Serb youth that was blamed on ethnic Albanians.
The Kosovan press carried an interview with a 13-year old boy who said he survived the incident on 16 March, in which the children were chased into the River Ibar by two local Serbs with a dog.
But an international investigator found there was no evidence for the story and blamed "reckless and sensationalist" media reporting for sparking the violence.
Street riots followed, leading many Serb families to flee the province as Albanian mobs attacked their homes.
Kosovo's UN administrator, Harri Holkeri, announced he was stepping down not long afterwards; a successor has yet to be appointed.
Kosovo's Serb and Albanian communities have been locked in an uneasy stand-off since a Nato bombing campaign drove Serbian security forces out of the province and drew it under UN control.
The Belgrade government, then under Slobodan Milosevic, was accused of war crimes against Kosovo's Albanian Muslims, who had been agitating for independence from Serbia.
Lingering hostility between the two communities have hampered international efforts to repair ethnic relations and reach a final settlement on the province's status.