A bomb attack by Sudanese government planes on a town in southern Darfur killed and wounded civilians, peacekeepers said on Sunday in the first independent verification of civilian fatalities.

The joint U.N./African Union UNAMID force said it did not know how many were killed when the jet fighter dropped at least two bombs on rebel-held Muhajiriya on Saturday.

Sudan's armed forces were not available for comment.

Air attacks in Darfur are forbidden under a 2006 peace deal and U.N. Security Council resolutions.

The raid followed more than a week of clashes and air attacks in and around the south Darfur town that have amounted to some of the worst violence in a year, said analysts.

The clashes have also added to tension in the build-up to an expected ruling from the International Criminal Court on whether to issue an arrest warrant against Sudan's president on charges of war crimes in Darfur.

UNAMID said Sudanese government forces attacked the town on Saturday a week after members of the Darfur rebel Justice and Equality Movement (JEM) took control of the settlement.

UNAMID spokesman Noureddine Mezni said peacekeepers from a UNAMID base in Muhajiriya reported that JEM forces opened fire after four government jets flew low over the town.

Shortly after, a single jet returned and dropped bombs in the southern outskirts of the town, he added. "Some civilians were killed and others were wounded," he said.

Up to 1,000 civilians also took refuge around the UNAMID camp after the attack, he added.

Members of a separate rebel group -- the Sudan Liberation Army's Unity faction -- said government ground and air forces attacked their positions near Um Saona and two other villages east of Muhajiriya on Saturday. The reports could not be verified.

International experts say almost six years of fighting has killed 200,000 and driven more than 2.5 million from their homes. Khartoum puts the death count at 10,000.