A UN investigator said Friday the Sudanese government was largely to blame for a humanitarian disaster in Darfur and its responsibility for large numbers of killings in the region was beyond doubt.

Investigator Asma Jahangir, a Pakistani lawyer, said a June visit to Darfur found overwhelming evidence government forces and militia they backed had executed large numbers of civilians.

But according to an agreement reached this week and released Friday, Sudan had now pledged to set up safe areas for uprooted villagers, work to disarm marauding militia and stop offensive actions by government troops in civilian areas.

The pact, reached Wednesday between Sudanese Foreign Minister Mustafa Osman Ismail and UN envoy Jan Pronk, outlines steps the Khartoum government must take within a month to improve security in its western Darfur region, site of what the United Nations calls the world's worst humanitarian crisis.

More than a million people have

been displaced by conflict there and Jahangir said the government was mostly to blame.

"It is beyond doubt that the government of the Sudan is responsible for extrajudicial and summary executions of large numbers of people over the last several months in the Darfur region," the Pakistani lawyer said in a report for the UN Sub-Commission on Human Rights, currently meeting in Geneva.

AFP adds: More than 200 members of a rebel group fighting Sudanese government forces in the war-torn Darfur region surrendered to the authorities, official media outlets reported yesterday.

According to the state-run Omdurman radio and several governmental newspapers, 10 field commanders and 200 men of the rebel Justice and Equality Movement (JEM) announced in the border town of Tina they were defecting and joining government forces.

Reports quoted the commanders as declaring at a ceremony held there for the occasion that their defection was prompted by the "unacceptable" treatment inflicted on them by rebel leaders.