The new hybrid UN-African Union force for Darfur, established by the UN Security Council and accepted by the Sudan government on 1 August, will improve security and humanitarian access, aid officials and analysts say.

According to a UN official in Darfur, the number of people recently rendered inaccessible by continuing violence had risen.

"In May 2006, the humanitarian community had access to almost everybody; now we do not have access to about half a million people," Mike McDonagh, north Sudan manager for the UN Office for the Coordinator of Humanitarian Affairs (OCHA), said.

"We are under attack every day, we have hijacks every day, we have aid workers attacked every day," he added. "Very many humanitarian staff were held at gunpoint [and] in many cases, were detained for hours and sometimes overnight and very often they were dumped in the desert."

At least 12,000 aid workers operate in Darfur, where an estimated 4.2 million people are affected by the humanitarian crisis.

"There are large areas to which we don’t have any access; areas where we have what we call sporadic access," McDonagh said. "We are starting to see the effect of the lack of access - an increase in malnutrition, more diseases that prey on children, diarrhoea."

Twelve humanitarian staff were killed across Darfur in 2006 and five since the beginning of this year, according to the UN. More aid vehicles have also been hijacked since, with the UN saying the hijackings have become more brutal.

"Darfur has become a very dangerous place for aid workers," McDonagh said.

Arusha talks

The UN Security Council resolution authorising the deployment of 26,000 troops and police endorsed the use of force to protect humanitarian workers and civilians under Chapter VII of the UN Charter, condemned the violence and called for a stop to aerial bombardments.

Sudan's Foreign Minister told reporters in Khartoum: "We announce our acceptance of the resolution." He said the revised and final text did take into consideration most concerns expressed by the Sudanese government about previous drafts.

"The Sudanese government sees that it can live with this resolution," Lam Akol added. "We will undertake to implement it faithfully; we expect others to also do the same."

Miriam Jooma of the Institute for Security Studies in South Africa, however, said: "We also need to look at the upcoming Arusha talks where political engagement will be discussed.

"It is important that the Chapter VII mandate was not compromised, although one missing aspect is that it does not give the UN the right to appropriate arms and related materials," Jooma said.

Troop-contributing countries are expected to announce their numbers within 30 days and the UN African Union Mission in Darfur (UNAMID) could establish operational capabilities by October.

Urging member states to support the operation, UN Secretary-General Ban Ki-moon told the Council: "You are sending a clear and powerful signal of your commitment to improve the lives of the people of the region and close this tragic chapter in Sudan's history."

Only one of three negotiating rebel groups signed an agreement with the government in Abuja, Nigeria, last year and more recently, the groups have split into more than a dozen unruly factions. The Arusha talks, planned for 3-5 August, are expected to bring together the non-signatories. "Arusha represents an important opportunity," Jooma said.