Rebel forces stormed a small African Union base in northern Darfur and killed 10 peacekeepers in an unprecedented attack on the beleaguered mission that threatened key peace talks set for October.

Several others were wounded and dozens were missing after about 1,000 rebels from the Sudan Liberation Army attacked the base in Haskanita late Saturday and eventually stormed it early Sunday, AU peacekeepers told The Associated Press in Haskanita.

The remaining AU peacekeepers were evacuated from the base under the protection of the Sudanese army, who routed the rebels out of the area. Some government troops could be seen plundering goods from the burned-out camp as an AU armored vehicle lay smoldering nearby.

"This is the heaviest loss of life and the biggest attack on the African Union mission," said AU spokesman Noureddine Mezni. "Our troops fought a defensive battle to protect the camp, but 30 vehicles eventually stormed it. ... The camp is completely destroyed."

The Darfur situation had been expected to improve after U.N. Secretary-General Ban Ki-moon visited Sudan early in September and announced new negotiations with Sudanese President Omar al-Bashir to settle the conflict that has killed at least 200,000 people and displaced 2.5 million.

Al-Bashir later announced a cease-fire during a visit to Rome, but violence increased in the ensuing weeks, with each side trying to improve its position ahead of the peace talks, scheduled to be held in late October in Libya.

Darfur rebels also have grown increasingly hostile to the AU peacekeepers, saying the force is not neutral and favors the government side.

Saturday's raid represents the first time since the 7,000-strong AU mission was deployed in June 2004 that one of its bases has been overrun, though soldiers have been regularly attacked. Several ambushes of AU forces in the past year have been blamed on the rebels.

"There is a war going on between the rebels and the government, and the AU is crunched in the middle," an AU officer said on condition of anonymity because of the sensitivity of the issue.

French Foreign Minister Bernard Kouchner called the storming of the base a "murderous and unacceptable act" and urged all parties in the conflict to show restraint.

"France condemns with the utmost firmness the attack on the camp of the African Union's mission," Kouchner said in a statement Sunday. "The international community must not spare any effort so that those responsible for this act do not remain unpunished."

The rebels did not comment on the latest attack, nor did the Sudanese military.

About 130 AU peacekeepers from Nigeria had been stationed at the Haskanita base, but they had been grounded since June because of the insecurity in the area. More than a third of the troops were unaccounted for late Sunday, said AU officials in Sudan.

Speaking in Ethiopia, the AU's top peace and security official, Said Djinnit, said 10 peacekeepers were killed in the attack, 10 wounded and about 30 remained missing. It was not immediately clear why there was a discrepancy between the number of missing peacekeepers.

"Some fled on foot and by car and have called us," said an AU officer in Haskanita, who declined to give his name because he is not authorized to speak to the media. "But we're very worried for some of them."

Rebel commanders told The Associated Press a few days earlier that they had been involved in heavy battles against government-allied forces in the Haskanita area for the past two weeks.

"The government has massed five or six janjaweed units who are converging on us," said Abdelaziz Ushar, a commander in the rebel Justice and Equality Movement, which fights alongside the SLA, referring to the camel-riding, pro-government militias that have led the attacks on rebels.

JEM rebels were reported to have evacuated Haskanita a couple of days ago, and AU peacekeepers in the camp said they suspected a splinter faction known as SLA-Unity had conducted the raid.

AU officers said they had observed several Sudanese helicopter gunships and MiG-19 fighter jets taking off for Haskanita on Sunday from their base in southern Darfur.

The underfunded AU force has been unable to stem the fighting in the war-torn western region and will soon be merged into a much more powerful AU-U.N. joint force. The first units of the 26,000-strong force will be deployed in October.