A prosecutor for the United Nations War Crimes Tribunal in The Hague says Yugoslavia has refused entry visas to tribunal investigators.

The prosecutor,Graham Blewitt, expressed surprise and frustration, telling a news conference in the Hague the tribunal could not understand Belgrade's decision because some cases being examined related to Serb victims of the war in Bosnia.

Last month, Belgrade barred tribunal investigators from the Serbian province of Kosovo, in breach of UN resolutions.