The worst drought to hit the Horn of Africa in 60 years is causing an Islamist militant group to change its mind about international aid agencies.

Al-Shabab says Muslim and non-Muslim aid groups would be allowed to provide food and other supplies to Somalis living in areas under its control.

Spokesman Sheik Ali Mohamud Rage told reporters in Mogadishu late Tuesday the groups would be allowed in as long as they first contact al-Shabab's drought committee.

Some groups, including the United Nations World Food Program, suspended operations in parts of Somalia because of threats from al-Shabab, which had banned the aid agencies.

The United Nations refugee agency said Tuesday drought and years of civil conflict have now driven one-quarter of Somalia's 7.5 million people from their homes, either to internal camps or to refugee camps abroad.

The refugee agency said it is especially disturbed by the high levels of malnutrition among the newest Somali refugees. It says more than half of Somali children arriving in Ethiopia are seriously malnourished, as are about 40 percent arriving in Kenya.

It says many children are so weak when they arrive that they die within 24 hours despite emergency care and feeding.

The United Nations and international relief groups say persistent drought in the Horn of Africa has left up to 10 million needing food aid. The British groups Oxfam and Save the Children launched an emergency appeal this week.

The groups are also raising alarm about conditions at the Dadaab refugee camps in Kenya. The U.N. says the camps, originally built to hold 90,000 people, now hold more than 380,000.