Sudanese forces bombed two rebel locations in Darfur just days after the head of the African Union's peacekeeping force visited the area to urge the rebels to join a cease-fire agreement, the AU said Sunday.

A Sudanese government aircraft on Friday bombed Anka and Um Rai in North Darfur province where Gen. Luke Aprezi had met on Wednesday with rebels, an AU statement said.

"When a bombing is made after I have visited an area, my credibility is involved," Aprezi told The Associated Press by telephone from Khartoum, Sudan's capital. "To that group, I don't have any credibility anymore."

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Aprezi declined to provide details about the Sudanese strike, which jeopardizes efforts to bring additional groups into the cease-fire that a single rebel faction and the government signed in May 2006, the AU said.

The AU statement said Sudanese officials had given consent ahead of time for Aprezi to meet with the rebels. Sudanese officials were not immediately available for comment.

Efforts to broaden the Darfur Peace Agreement have failed and the United Nations and aid workers report that violence has increased since the signing.

Sudan's president agreed last week to accept U.N. support to strengthen the underfunded 7,000-strong AU peacekeeping force charged with monitoring the cease-fire in the troubled area approximately the size of France.

The first group of U.N. experts — 43 military staff officers and 24 policemen — have arrived in Sudan and will deploy to Darfur after a week of orientation, Aprezi said.

Conflict erupted in Darfur in February 2003 when the mostly African ethnic tribes rebelled against the Arab central government. Violence has claimed some 200,000 lives and forced 2.5 million people from their homes in this vast arid area.