Four Jordanian police officers serving with the United Nations in Kosovo have been cleared of involvement in a shoot-out with colleagues, officials say.
It is still not clear what provoked the gunfight between colleagues
Three American officers and a Jordanian sergeant died in the incident, which took place at a Kosovo prison in April.
A prosecutor investigating the gunfight had concluded there was "no reasonable suspicion" the Jordanians had committed an offence, a UN spokesman said.
Kosovo is home to a multi-national UN police force of some 3,500 officers.
Their mission is to train and support a local force of some 6,000 officers working amongst Kosovo's bitterly divided Serb and Albanian communities.
The clash is believed to have begun when the Jordanian sergeant opened fire on a bus carrying a team of Americans away from a prison visit.
In the ensuing gunfight, three Americans were killed and 11 were injured.
US officers eventually shot dead the Jordanian sergeant.
The four Jordanian officers were detained at the scene of the shooting on the suspicion that they had failed to help the victims.
One of the officers faced a further charge of being an accessory to murder and causing bodily harm.
The motive for the attack remains unclear.
The UN authorised an international peacekeeping and police force for Kosovo in 1999, after Nato air-strikes pushed back Serb forces that were accused of war crimes against ethnic Albanians in the province.