Heavy fighting in southern Darfur has killed scores of rebels and government forces over the past week, and the Sudanese air force has bombed several villages, rebels and international observers in Darfur reported.
The clashes began Aug. 1 when a coalition of rebels, including members of the Justice and Equality Movement (JEM), captured the strategic town of Adila, where Sudanese troops were stationed to protect the only railway linking Darfur to Sudan's capital, Khartoum, rebels said.
The Sudanese army and its allied janjaweed militias "were summarily defeated, leaving behind heavy weapons and ammunition," JEM said in a statement.
The group said the offensive was led by Abdelazziz Ushar, a Darfur field commander previously fighting a separate rebellion in eastern Sudan.
A senior international observer in Darfur said on Thursday that Sudanese forces had recaptured Adila, located near South Darfur's border with the neighboring region of Khordofan, but reported clashes were ongoing.
"It seems over 100 [Sudanese] soldiers or janjaweed have been killed," the official said on the telephone.
At least 10 rebels were killed and 15 injured, he said, speaking on condition of anonymity because he was not authorized to speak to the media.
Rebels said they launched the offensive because the janjaweed were burning villages in the area.
The African Union mission in Darfur confirmed there had been heavy fighting, but said it had no further details.
Rebels and international observers said the fighters seized more than 50 government vehicles and some heavy armaments during the offensive.
Meanwhile, Sudan's air force bombed at least four villages in the area this week, observers and rebels said, but there were no reports of casualties because many of the civilians have fled.
One of JEM's leaders said his group shot down a government MIG-29 fighter jet on Wednesday that was participating in the bombings, a claim denied by the government and disputed by other rebels.
Abdullahi el-Tom said the aircraft's wreckage had been found 4.5km south of Adila, but the pilot had not been located.
Rebels from a faction of the Sudan Liberation Movement fighting alongside JEM told international observers the jet crashed because of a mechanical problem.
Army spokesman General Osman Mohamed al-Agbash denied that rebels had downed a government jet, but indicated the military had faced heavy fighting in Adila.
"JEM wants to tell the international community that the army has used air bombing in [the] recapturing of Adila," the Sudan Media Center, a news service deemed close to the government, quoted al-Agbash as saying.
There was no comment on military casualties.
Military flights are banned over Darfur by several UN resolutions and peace agreements, and Sudanese authorities routinely deny conducting air raids.
Sudanese President Omar al-Bashir visited Darfur last month and said the region was largely pacified. But the UN mission in Sudan said there have been clashes between rebels and the government in northern Darfur in recent days.
The heavy fighting in Adila came as the UN and African Union sponsored a Darfur rebel conference in Arusha, Tanzania, to relaunch talks with the government after a peace agreement in May last year between Khartoum and one rebel faction proved largely ineffective.
The UN Security Council on Thursday welcomed "the substantial progress made" at last week's conference and called on all parties "to move from pre-negotiations to negotiations as soon as possible."
The council also called on the parties "to demonstrate their commitment to the political process through concrete actions, in particular cessation of hostilities."