Clashes in Sudan's Darfur region have reportedly killed dozens of people including rebels and government forces. The rebels say that subsequent air raids by the Sudanese government has forced 25,000 people to flee their homes in the troubled region. Nick Wadhams has more from Nairobi.

The latest round of fighting began last week with an attack by rebels from the Justice and Equality Movement on the town of Adila. The subsequent clashes between the rebels and government forces raises new fears that efforts to end the Darfur conflict will be lost just a week after the U.N. Security Council authorized a peacekeeping force of 26,000 for the region.

The peacekeepers are not expected to arrive for months but will find themselves paralyzed if there is no peace to keep. An estimated 200,000 people have been killed and more than two million others have been displaced in Darfur since fighting began in 2003, and many had hoped the peacekeeping force was a sign of better things to come.

The Justice and Equality Movement says it launched the latest attacks starting a week ago on Adila, where Sudanese government forces were guarding the sole rail link between Darfur and the capital Khartoum to the west. The government says it has since recaptured the town.

The rebels contend that government forces had resumed aerial bombing in violation of U.N. Security Council resolutions that banned such flights. It also claimed to have shot down a government jet, a claim that Khartoum denies.

Another rebel faction, the Sudan Liberation Army of Minni Minawi, recently clashed with government forces near the city of Nyala.

The spokesman for the small African Union peacekeeping force now in Darfur, Noureddine Mezni, says that is a bad sign because the SLA was among the groups that signed a peace deal with the government in 2006.

"Even the signatories cannot solve their grievances through the proper channels but rather resort to hostile acts which further delays the peace process," said Mezni. "Really we are calling on all the stakeholders to stop fighting, talk to each other and to set their problems through peaceful means. Everybody now agrees that there is no military solution to the conflict in Darfur."

The attacks are also drawing criticism from Darfur's other rebel groups because they came either just before or during negotiations over the weekend in Arusha, Tanzania, where the rebels agreed to present a united front ahead of possible peace talks with Khartoum.

A separate faction of the Sudan Liberation Army which did not participate in those talks called the Justice and Equality Movement attacks a bid for attention. Yahia Bolad is a London-based spokesman for that faction.

"This is not the first time. When the negotiation started, they started to make disturbance for the negotiation," said Bolad. "This is their way to make attraction to themselves that they are there but we have commitment to the ceasefire agreement. If you are going to negotiate in Arusha, this is a double standard."

Analysts had said that an important success of the Arusha talks was the fact that the rebels had managed to speak with one voice. Now, if individual rebel groups are again launching attacks on their own, the Khartoum government could see the rebels as divided and weak, and may be less inclined to negotiate with them.