By Andrew Heavens

KHARTOUM, Sept 15 (Reuters) - Thousands of villagers have been forced to flee their homes after more than a week of heavy clashes between Sudanese forces and rebels in North Darfur, aid sources said on Monday.

Entire villages have been abandoned after residents took shelter in surrounding mountains and open land, cut off from food aid and clinics, humanitarian officers said.

Darfur rebel groups said Sudanese soldiers and allied militias launched a string of heavy ground and air attacks on their positions north of the town of Kutum and southwest of Tawila in north Darfur throughout last week and over the weekend.

One rebel leader said fighting continued on Monday, although his statement could not be verified independently.

A spokesman for Sudan's armed forces last week said soldiers had entered some of the areas mentioned by the rebels. But he said troops were securing roads against bandit attacks and did not mention any clashes.

No one was available to comment on reports of more fighting on Monday.

"The areas have emptied out," said one aid source, speaking on condition of anonymity. "People are moving, but at the moment it is unclear whether they are going to other villages, to the mountains, to the camps.

"We are talking thousands of people, but at the moment it is impossible to say how many thousands," said another source who asked not to be named.

FOOD LOW BEFORE HARVEST

The reported clashes came at one of the worst times of year for villagers, when food supplies are lowest just before the harvest.

Emergency food deliveries were also recently cut in large parts of North Darfur when the German charity Welthungerhilfe, also known as German Agro Action, suspended work last month after threats against its staff.

The United Nations' most senior humanitarian official in Sudan, Ameerah Haq, told reporters late on Sunday that U.N. officers had not been able to access remote areas to get information on the impact of the reported clashes.

"We are very worried about what impact these operations is having on the civilian population ... With the government attacks there is obviously displacement of civilian populations. But we don't have reliable numbers," she said.

Haq said that before the fighting U.N. figures showed about 10,000 people regularly received food aid in and around the villages of Disa and Birmaza, north of Kutum. But it was impossible to say how many had fled.

Frankfurt-based aid group Partner Aid International said eyewitnesses had told staff its clinic in Khazan Tunjur and four surrounding villages southwest of Tawila had been burned to the ground during the violence on Sunday morning.

"Large groups of the remaining population are fleeing the area," it added in a statement, saying that its workers had evacuated the area on Tuesday.

The undermanned joint U.N./African Union UNAMID peacekeeping force in Darfur last week said government forces had barred it from entering areas reportedly hit by the fighting and added it did not have helicopters needed to fly over the affected region.

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.

(Editing by Robert Hart)

AlertNet news is provided by