Donors have contributed less to Somalia because many areas are too dangerous for aid agencies to operate in, U.N. officials said Friday.

Contributions for humanitarian aid have been $571 million for 2009 so far, the Integrated Regional Information Network said. In 2008, donors gave $615 million.

"Some of the largest donors in 2008 have given much less or almost no support so far this year," said Kiki Gbeho, head of U.N. Office for the Coordination of Humanitarian Affairs for Somalia.

About 3.6 million people in Somalia depend on humanitarian assistance, the United Nations says. Food planners say some areas controlled by Islamist rebels in the central and southern part of Somalia are just below famine level on a five-point scale of food security.

Many donors have told the U.N. aid agencies they fear rebel groups would "tax" contributions.