Three former KLA rebel fighters have been arrested in Kosovo by EU police over war crimes committed against civilians in 1999.
A spokesman for the EU's rule of law mission Eulex said two of the men were current members of the Nato-trained Kosovo Security Force (KSF).
No details were given of the charges against the three suspects.
But reports suggest the case relates to the murder of two supporters of moderate politician Ibrahim Rugova.
Rugova, who died of lung cancer in 2006, served as Kosovo's first president after its ethnic Albanian majority broke away from Serbia in 1999.
"The suspects are charged with war crimes against the civilian population," said Eulex spokesman Blerim Krasniqi, quoted by Reuters news agency.
The three, he added, were former members of the Kosovo Liberation Army (KLA), the ethnic Albanian rebels who fought the Serbian authorities during the war, which ended when Nato intervened.
Tahir Rrecaj, a lawyer for one of the men, said the detainees were suspected of killing two ethnic Albanian civilians in June 1999, just days after the war ended, Reuters reports.
Local media say the victims were supporters of Rugova, AFP news agency reports.
The KSF is a lightly armed force of 2,500 tasked with responding to crises, which was established in 2009.
Its predecessor, the Kosovo Protection Corps, absorbed many former KLA fighters.
Some 10,000 people are believed to have died during the Kosovo war, most of them ethnic Albanians.