The WFP also sent two doctors to the city, as well as enough medical supplies from the UN's children's agency UNICEF and the World Health Organization to cover the urgent needs of 50,000 people for a month.

"This is a breakthrough for the UN humanitarian operation in Libya and allows us to reach tens of thousands of people who are caught in one of the fiercest areas of conflict," said WFP Executive Director Josette Sheeran.

"The operation in Libya is complex and dangerous, but we are exploring every possible avenue to get food to the hungry," Sheeran added.

UNICEF Executive Director Anthony Lake said: "These supplies are a lifeline to them and all those trapped in the fighting."

The United Nations on Wednesday called for a halt to hostilities around Misrata, saying several weeks of "heavy shelling" by Moamer Qadhafi's forces had killed or wounded hundreds.