Special UN envoy to Afghanistan, Lakhdahr Brahimi, is expected to meet with the new interim government leader and American diplomats in Kabul to discuss unconfirmed reports of civilian casualties during last week's bombing raid in Paktia province.

The United Nations says it has reports from reliable sources that an air raid last Saturday on a compound in Niazi Qalaye village in Paktia killed at least 52 civilians including women and children.

The U.N. spokeswoman in Kabul, Stephanie Bunker, says the reports indicate that there were no Taleban or members of Osama bin Laden's al-Qaeda organization among the dead. She would not reveal who the U.N. sources are. "I really cannot get into the sources. But the reason why we reported it this week is because we felt the sources were credible," she said.

Earlier this week, a U.S. military spokesman confirmed that American warplanes destroyed a compound in the village after two surface-to-air missiles were fired at the planes. He said that the compound housed Osama bin Laden's al-Qaeda fighters and their Taleban allies, not civilians.

Since the United States began its bombing campaign in Afghanistan on October 7, there have been some reports of apparently mistaken attacks on civilians. But none of the reports have been independently verified.

Meanwhile, anti-Taleban leaders in southern Afghanistan say negotiations for the surrender of deposed Taleban leader Mohammed Omar and 1,500 of his fighters have reached a crucial stage.

A senior intelligence official in the southern city of Kandahar says the leaders are working on the final terms for their surrender. Mohammed Omar - the U.S. second most wanted man behind Osama bin Laden - is believed to be holding out near the town of Baghran, about 160-kilometers northwest of Kandahar.

In Kabul, a defense ministry official in the new interim government has confirmed that the Taleban's intelligence chief, Qari Ahmadullah, was killed December 27 during a U.S. bombing attack in Paktia province. He is believed to be the highest-ranking Taleban official killed during the U.S. led military campaign.