Fighting between rival Arab tribes has rocked Sudan's Darfur region for a second day, after 100 people were reported killed in unrest that has already left hundreds dead this year.

Battles were taking place in the Adila area of southeastern Darfur on Sunday, the sources said.

"The fighting today spread to many areas," said a member of the Rezeigat tribe. "I saw some wounded Rezeigat taken to the hospital in Ed Daein on Land Cruisers."

A Maaliya resident confirmed the fighting south of Adila, and a doctor in Nyala city to the west told AFP news agency that some wounded Maaliya had been taken there for treatment.

"We clashed with Maaliya... and we destroyed a compound of theirs and killed 70 of them," another Rezeigat source said, declining to be named.

They were not able to give casualty figures for Sunday's fighting but tribal sources said dozens had died on Saturday.

Inter-ethnic fighting has been the major source of violence in Darfur this year, where an estimated 300,000 people were displaced in the first five months alone, according to African Union-UN peacekeeping mission in Darfur (UNAMID).

Prior to this year's surge of violence, there were already 1.4 million people in camps for those uprooted by the conflict in Darfur.

Source: Agencies