The AU Mission in Sudan (AUMIS) reported a "heavy toll on the civilian population" after aerial bombardments, which suggests government forces' involvement, and ground attacks were carried out by Arab militia, in Birmaza in northern Darfur, on Wednesday and Thursday.
Andrew Simmons, Aljazeera's correpsondent in Dafur, reported that AU sources had said up to 70 civilians were killed in the attacks, but that the Sudanese government had not yet confirmed this figure.
The AU mission said that this was a complete violation of the Darfur Peace Agreement and called for rival parties, who have failed to heed several previous appeals, to refrain from hostilities and bring an end to the conflict.
"AUMIS calls on all the parties to the conflict to exercise restraint, even in the face of provocation, and desist from carrying out condemnable indiscriminate attacks which cause severe civilian casualties and the destruction of livelihoods," the statement said.
"AUMIS calls on all the parties to the conflict to exercise restraint, even in the face of provocation,...".
Send us your views
Kofi Annan, the out-going UN secretary-general, announced on Thursday that authorities had agreed on the deployment of a combined UN and AU peacekeeping force in the region, but this was later played down by Khartoum.
Diplomats and observers who attended the talks that led to the apparent compromise said Khartoum's stance was not entirely clear, as Sudanese officials repeated that no UN peacekeepers would be allowed on the ground.
Aid officials have complained that the situation in Darfur, an arid region the size of France, has deteriorated in recent months and have said that many people will succumb to the conflict or disease if the world fails to restore peace.
In other developments, a peace accord was signed in Tripoli, the Libyan capital, on Saturday between the Sudanese government and the Sudan Liberation Movement – Faisal Abul Qassem Imam Faction.
The agreement, which calls for compensation to be given to displaced Dafuris, the disarming of militias and that the SLM be represented in government posts, was signed by Magzoub al-Khalifa, adviser to the Sudanese president, and a senior figure from the SLM.
Many rebel factions are still yet to sign an agreement with the government and are continuing their attacks on the civilian population.
A new round of talks is planned at the AU peace and security council next Friday.