UN aid chief Martin Griffiths said on Wednesday he was seeking assurances from Sudan’s warring factions on the safe delivery of aid after six trucks of humanitarian supplies were looted and air strikes in Khartoum undermined a new ceasefire.

“We will still require agreements and arrangements to allow for movement of staff and supplies,” Griffiths said from Port Sudan, where many people have fled as the army and Rapid Support Forces (RSF) have battled for three weeks.

“We will need to have an agreement at the highest level and very publicly, and we will need to deliver those commitments into local arrangements that can be depended on,” he told reporters via video link from the Red Sea port.

Air strikes were heard in the capital Khartoum on Wednesday even as warring factions agreed to a new seven-day ceasefire from Thursday.

The conflict has created a humanitarian crisis, with about 100,000 people forced to flee with little food or water to neighbouring countries, the United Nations said. Aid deliveries have been held up in a nation of 46 million people.

Reuters