Serbia launched an investigation into five policemen believed to have committed war crimes during the 1998-99 conflict in Kosovo, the office of the war crimes prosecutor said on Friday.
"The office of the war crimes prosecutor requested an investigation against five members of the special police unit who are believed to have been committed war crimes against civilians and prisoners of war," the statement said.
"The prosecution ordered their detention."
Sources close to the investigation said that four of the five were arrested on Friday.
NATO stopped in 1999 Serb forces' killing of civilians in a two-year counter-insurgency campaign.
In February, the United Nations war crimes court in The Hague sentenced five Serbian officials, including a former army chief and a deputy prime minister, to prison terms of between 15 and 22 years.
The five were found guilty of mass killings of Kosovo Albanian civilians during the 1998-99 conflict between Serb forces and separatist guerrillas.
Güncelleme Tarihi: 15 Mart 2009, 12:28