Updated

Gen. 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 Tuesday.

David Harland, the second prosecution witness to testify at the former Bosnian Serb military chief's U.N. trial, said he met often with Mladic during the 1992-95 war and noticed him becoming increasingly belligerent as the conflict went on, including threatening to kill civilians in the U.N.-protected enclaves, which included Srebrenica.

Mladic faces 11 charges, including genocide, for allegedly masterminding Serb atrocities throughout the war that culminated in the 1995 massacre of some 8,000 Muslim men in Srebrenica. He denies wrongdoing.

Harland's testimony is key to prosecutors because he regularly met Mladic and can provide an insight into his actions and motivations. He has testified previously at tribunal trials, including those of Mladic's political master, Radovan Karadzic, and former Yugoslav President Slobodan Milosevic.

While the tribunal has already often proved that massive crimes were committed during the Bosnian war that left 100,000 dead, it can be hard to tie such atrocities to senior leaders, and that is the challenge for prosecutors in Mladic's case.

Harland said the United Nations took seriously Mladic's threats, which were made toward the end of 1993, some 20 months before the Srebrenica massacre.

"I think our view on the threats was he was like a bully. If the opportunity arose to carry out these threats, probably he would do it. But they were not really statements of plans," he said.

Bosnian Serb forces overran Srebrenica in July 1995, separated women, children and the elderly from men and then systematically murdered the men in mass executions before plowing their bodies into mass graves. The bloodbath was Europe's worst massacre since World War II and has been labeled a genocide by both the Yugoslav war crimes tribunal and the International Court of Justice.

Harland wrote regular reports for the U.N. on meetings with Mladic and noticed the general becoming more bellicose as he felt his political masters were failing to capitalize on his army's gains.

Mladic and other Bosnian Serb military leaders "felt that the political civilian leadership had not performed well and that they might have to undertake further military actions," Harland said.

As Harland was led into court to testify, Mladic glared at him over the top of his reading glasses. Harland did not meet his gaze.

Earlier, the first prosecution witness, Bosnian Muslim Elvedin Pasic, finished his testimony with a tearful plea for help to find his father's body.

In heart-wrenching testimony Monday, Pasic told the court how he was separated from his father by Serb forces in 1992 when he was 14 and never saw him again. Prosecutors say the father was among some 150 men massacred by Serbs early in the war.

"I miss my dad," Pasic said, choking back tears Tuesday.

He asked that if anybody had information about the whereabouts of his father's body, "please come forward and let me find my dad."