"We are concerned about the security of women once they leave the security perimeters around aid distribution sites," said Elisabeth Byrs, a spokeswoman for the UN's Office for the Coordination of Humanitarian Affairs.

"They are often threatened and attacked by armed men who steal the aid they have received," she added.

UN peacekeepers have had difficulty protecting food aid stores from looters in Gonaives, which was devastated by fierce floods that have left at least 1,554 people dead and 904 missing when Tropical Storm Jeanne hit the area last week.

Byrs called for Haitian authorities to step up security in the area, and take greater involvement in affairs generally.

She also called for a change in mentality among Haitians as women wait in queues for hours to get food aid and then carry home themselves the heavy sacks of rice while men often stand by idly.

Some 700 soldiers from the United Nations Stabilization Mission in Haiti (MINUSTAH) have deployed in Gonaives to protect food aid supplies and assist in its distribution.