The chaos underscores the dangers and challenges of getting help to a nation that has been essentially ungoverned for two decades and now has a severe famine. There are 9,000 African Union soldiers in the capital, but their main mission is to fight al-Qaeda-linked Islamists.
Aid workers are puzzling over how to help the starving without helping gunmen who prey on the refugees, compete for security contracts to guard the food, or steal it and take a share of the profits when it's sold at market.
The situation echoes the 1992 famine that prompted deployment of a U.S.-led multinational force to safeguard delivery of food to Somalia's starving. That international intervention collapsed in 1993 after two U.S. Black Hawk helicopters were shot down and 18 servicemen killed in a single battle in Mogadishu.
U.S. and U.N. officials acknowledge that some aid in Somalia is bound to be stolen during delivery.
"Will there be some looting? Of course there will be," WFP spokesman David Orr said. "What we have to do is try to minimize it. This is the highest-risk environment in the world. . . . The safety of our staff and getting food into the right hands are our highest priorities."
Friday's food distribution was organized by Mogadishu's mayor and had been delayed two days as officials tried to shore up security arrangements. Orr said the distribution started smoothly about 6 a.m. but degenerated a couple of hours later.
The drought and famine in Somalia have killed more than 29,000 children under age 5 in the last 90 days in southern Somalia alone, according to U.S. estimates.
Somalian Prime Minister Abdiweli Mohamed Ali visited the camp after the violence. Ali said an investigation would be opened and promised harsh punishment for anyone found guilty.