A United Nations court on May 22 ordered two former Serbian state security officials to be held in jail until their retrial starts next month.

The International Criminal Tribunal for the former Yugoslavia (ICTY) said it has asked Serbia’s Ministry of Internal Affairs to return Jovica Stanisic, 66, and his deputy, Franko Simatovic, 67, to the UN Detention Unit in The Hague by May 30.

The two were acquitted in their first trial for war crimes committed during the 1990s Balkan conflicts, but that decision was quashed in late 2015 on appeal with the judges saying several legal errors had been made in the trial, which lasted from June 2009 to January 2013.

The new trial will begin on June 13, the ICTY said.