RWINDI, Congo - Congo’s army clashed with rebels in some of the worst fighting in a week despite the rebel leader’s promise to support a cease-fire, the United Nations and witnesses said Monday.

The two sides battled Sunday night in Rwindi, about 75 miles (125 kilometers) north of the eastern provincial capital of Goma. About 150 people took refuge outside a U.N. peacekeeping base here, huddling beside a white shipping container as mortar shells and artillery fire rained down.