''The shooting struck a huge blow at the very idea of peacekeeping," said Alex Anderson, the Kosovo project director of International Crisis Group, a Brussels-based think tank. It will ''affect the perception of the peacekeepers among the population."
In Belgrade, the Serbian Orthodox Church said the shooting ''proves that the UN does not control the situation."
The church had earlier criticized the UN mission as failing to protect Serbs and Serb churches during the recent riots in Kosovska Mitrovica.
Kosovo became a UN protectorate in 1999, after NATO launched a 78-day air war to stop former president Slobodan Milosevic from cracking down on ethnic Albanians seeking independence.
The 3,500-strong UN police force includes 450 US officers, most of whom work for Dyncorp, a private company that trains police, corrections, and judicial officers who work in places such as Kosovo and Iraq. The UN police force works alongside 6,000 local police officers.
It is still unclear what sparked the shooting between officers from the police and correctional units of the UN mission. Ten Americans and one Austrian were also injured in the violence.
Yesterday, UN investigators went door to door in apartment buildings overlooking the prison compound, interviewing witnesses.
Officials denied rumors that a quarrel about the war in Iraq had sparked the gun battle.
''As far as we know, there was no communication between the officer who fired and the group of victims," said Neeraj Singh, a UN spokesman.
But a US police officer serving with the UN mission said the shooting was ''clearly an attack against Americans." The officer, who spoke on the condition of anonymity, did not elaborate.
