MOGADISHU - Somalia's al Shabaab militants said on Monday they had banned Muslim aid agency Islamic Relief from areas under their control, a move that would deprive 1.3 million people of food, clean water and health care.

Islamic Relief, one of few international aid agencies able to work in al Shabaab-run areas, said it had not been notified by the rebels that its permit had been revoked and that a ban would also threaten access to areas under government control.

Faced with a military offensive by African Union and Somali forces, the al Qaida-linked insurgents have pulled out of a number of urban strongholds in southern and central Somalia. They still hold sway over vast rural areas where the central government and regional administrations have minimal control.