Medical officials say Shiite rebels and their allies randomly have bombed an area north of the southern city of Aden, killing at least 45 people.

The rebels are fighting to thwart an offensive by Saudi-backed troops and local fighters.

On Sunday, the officials said hundreds of residents fled Dar Saad, north of Aden, amid intense shelling from the rebels. They said at least 45 people, believed to be civilians, were killed. The officials spoke on condition of anonymity as they weren't authorized to brief journalists.

The Saudi-backed fighters, backed by Saudi-led coalition airstrikes, pushed the rebels out of Aden's airport and two major neighborhoods last week. The rebels vowed to retaliate.

Aden has been the scene of some of the war's most intense ground fighting since March.