KHARTOUM (Reuters) - Insurgent groups said Sudanese forces launched "very heavy" ground and air attacks on rebel positions and villages in North Darfur on Saturday, in the latest of a string of reported assaults.
No one was immediately available for comment from Sudan's armed forces but officers have repeatedly denied that there is military activity going on in the area in recent days.
The accusations come at a particularly sensitive time as Khartoum steps up diplomatic efforts to block moves by the International Criminal Court to indict Sudan's president for genocide and other alleged crimes in Darfur.
"The Antonovs have been bombing everywhere," said Ahmed Kubur Jibril, from the rebel Sudan Liberation Army's Unity (SLA-Unity) faction, speaking from Darfur by satellite phone.
"Sometimes they have been bombing SLA positions. Sometimes they have been bombing villages and civilian areas. There were soldiers in many vehicles."
Jibril said the attacks on the villages of Tarny, Khazan Tungur and surrounding settlements south west of the town of Tawila, were part of a week-long offensive on insurgent positions in North Darfur.
Fighters had given him reports of a number of deaths among civilians and injuries among rebels. But it was impossible to get definite figures while the fighting was going on, he added.
Ibrahim al-Helwu, from the branch of the SLA led by Abdel Wahed Mohamed el-Nur, said a large number of civilians had fled the area with their animals since the attacks began on Saturday last week.
"There has been some very heavy fighting. The Antonovs have been continually bombing us," said al-Helwu. "They have gone back to the tactics they were using against us at the beginning of the conflict."
Other rebel leaders have accused the Sudanese government of launching the attacks to secure key transport routes and to grab territory ahead of possible negotiations led by the new joint U.N./African Union mediator for Darfur, Djibril Bassole.
A spokesman for the U.N./A.U. UNAMID peacekeepers in Darfur said he was checking into the rebel reports of fresh fighting.
The undermanned and poorly equipped mission earlier said it could not confirm reports from rebels in North Darfur as it did not have bases in the area or enough helicopters to fly over the locations.
But it added that officers had seen large scale movements of Sudanese army equipment, suggesting "intense military activity" was taking place.
Armed forces spokesman Brigadier Uthman al-Agbash last weekend denied any military activities were taking place in Darfur and said soldiers were concentrating on securing roads through the remote region to protect aid convoys.
The state Sudanese Media Centre on Friday reported police had been arresting members of a large "criminal gang" in North Darfur that had been looting markets.
Djibril Bassole on Friday put out a statement saying he was "concerned" about reports of continued fighting in Darfur and urged all sides to "cease all military activities in order to protect civilians and create conditions for political dialogue".
More than five years of fighting in Darfur has killed 200,000 and driven more than 2.5 million from their homes, say international experts. Khartoum says 10,000 have died