General Ratko Mladic threatened to wipe out the civilian populations of enclaves in eastern Bosnia in a chilling foreshadowing of the Srebrenica massacre, a former United Nations official told the Yugoslav war crimes tribunal.

The first witness is set to give evidence at the resumed war crimes trial of former Bosnian Serb military chief Ratko Mladic, about Serb forces violently purging his village in 1992.