Spokesman Sean McCormack said investigators are trying to determine whether the murders in the predominantly Albanian province were politically motivated.
"The capability of Kosovo's institutions to solve this kind of murder and prevent its recurrence will be a critical test of Kosovo's ability to govern itself," McCormack said.
Several thousand Kosovo Serbs held demonstrations earlier in the day on 29 August to express their anger over the drive-by shooting late on 27 August that left two Serbs dead and two others wounded.
Demonstrators also demanded more security and freedom of movement. Kosovo has been administered by the United Nations since 1999.
(compiled from agency reports)
"The capability of Kosovo's institutions to solve this kind of murder and prevent its recurrence will be a critical test of Kosovo's ability to govern itself," McCormack said.
Several thousand Kosovo Serbs held demonstrations earlier in the day on 29 August to express their anger over the drive-by shooting late on 27 August that left two Serbs dead and two others wounded.
Demonstrators also demanded more security and freedom of movement. Kosovo has been administered by the United Nations since 1999.
(compiled from agency reports)
