OCHA has also complained that a UN humanitarian worker was deported from the South Darfur area, while a UN food truck was attacked by the Arab militia knows as the Janjaweed.

The latest Darfur Humanitarian Profile estimates that more than 2 million people are being affected by the conflict, compared to 1.1 million reported in the April Profile. Approximately 432,329 internally displaced persons (IDPs) are in West Darfur, 320,906 in North Darfur and 233,138 in South Darfur. The rest are refugees who fled to neighbouring Chad.

"An OCHA Senior Humanitarian Affairs Officer in Nyala was deported from South Darfur. This was unacceptable treatment for UN staff," the update says, without naming the deportee.

Meanwhile, "a UN vehicle came under attack on the Zalengei-Mornei road last Wednesday. A truck carrying WFP food, clearly marked with WFP signs, travelled in proximity of two government trucks when it came under Janjaweed attack," it added, referring to the UN World Food Programme.

"Two bags of WFP grain were looted, [and] the WFP-hired truck driver was robbed, beaten and subsequently hospitalized. The government drivers were also beaten [and] robbed, and one of the drivers was shot and injured."

Although IDPs have repeatedly said they would return home to West Darfur only when the Janjaweed militia are disarmed and when there is security, the government was insisting on immediate IDP return. Traditional leaders were being pressured or persuaded to cooperate, or else they were replaced, OCHA said.

The authorities in West Darfur's capital, Geneina, replaced "the vocal community committee" of traditional leaders in Sisi camp with more conciliatory representatives, it said.

In South Darfur, IDPs who accept food aid were subject to Janjaweed militia predatory attacks, OCHA said. "Agencies agree that any distribution of shelter and [non-food items] will commit them to close monitoring of deliveries to minimize the risk to recipients."