Pakistan has refused to hand over a retired general, who headed the spy agency ISI, to an international tribunal investigating war crimes in Bosnia. Media reports said, the Pakistan government cited medical grounds as its reason for not handing over former Inter-Services Intelligence chief Lt Gen (retired) Javed Nasir to the International Tribunal of Hague. The tribunal had demanded custody of Nasir for his alleged support to Bosnian Muslim fighters despite an embargo by the United Nations. The Bosnian Muslims were fighting against the Serbian army in the 1990s. The summons for Nasir came when Serbian army officials were put on trial by the international tribunal for war crimes and crimes against humanity in Bosnia.