Kenya ? Fears of a looming war in Somalia are hampering relief efforts for up to 1 million people hit by severe flooding, a senior U.N. official said Friday.

Eric Laroche, the U.N.’s humanitarian chief for Somalia, said a “corridor of peace” is needed so aid can reach 400,000 people who have fled their homes to escape the worst flooding in a decade.

Up to 1.8 million people have been hit by floods in Kenya, Somalia and Ethiopia resulting from heavy rains in East Africa, with 1 million of them in Somalia, the U.N. said. Aid organizations say more than 100 people have been killed by flooding this month in the region.

In Somalia, a powerful Islamic movement has expanded control across much of the country, threatening the authority of the fragile and weak transitional government. The administration is backed by Ethiopia, the regional powerhouse.