New York  - The 13 relief organizations expelled by the Sudanese government last week provided 50 per cent of humanitarian assistance to civilians in need in Sudan's Darfur region, the top UN humanitarian coordinator said Monday.

John Holmes, the UN undersecretary general for emergency relief coordinator, said at UN headquarters in New York that neither Khartoum nor the UN or other non-governmental organizations can sufficiently provide assistance alone.

He said all sides have to work together to meet the needs of an estimated 4.7 million Darfurians following years of warfare.

Khartoum last week cancelled work permits and expelled 13 foreign relief groups after the International Criminal Court at The Hague issued an international arrest warrant Sudanese President Omar al- Bashir, who it charged with crimes against humanity and war crimes. Khartoum retaliated by clamping down on Darfur.

"That is why the (humanitarian) challenge is so daunting if the decision of the government of Sudan is not reversed," Holmes said. He said the groups expelled accounted for about half of humanitarian capacity in Darfur.

"We do not, the NGOs do not and the Sudanese government does not have the capacity to replace all the activities that have been going on, certainly not on any short- or medium-term basis," he said.

The UN said Secretary General Ban Ki-moon has been trying to convince the Sudanese government to rescind the revocation of relief groups' work permits so they can resume their humanitarian assistance. The groups expelled included Oxfam, CARE and the French group Doctors Without Borders.

Representatives of the UN and relief groups had been facing harassment at the hands of Sudanese security forces while the ICC considered arresting al-Bashir, who denied all responsibility in the killing in Darfur. The UN said more than 300,000 people have died in Darfur's ethnic conflict since 2003.

Holmes said at a press conference that equipment, cars, computers and belongings of expelled NGOs had been confiscated as they prepared to leave Sudan last week. He said Sudanese security forces have also seized warehouses of the World Food Programme at a time when water and food has become more scarce in Darfur. (dpa)