MOGADISHU, Somalia — Mogadishu’s dominant clan said yesterday that it has brokered a truce with Ethiopian military officials who are supporting Somalia’s government, even as mortar shells continued slamming into the capital for a fourth day.

Ahmed Diriye, the Hawiye clan spokesman, said fighting in Mogadishu should end within hours. Ethiopian officials were not immediately available for comment.

Somali government troops and their Ethiopian allies have been waging a fierce offensive since Thursday to wipe out Islamic insurgents, sparking some of the heaviest fighting in 15 years in the capital. Untold numbers of civilians have been killed and hundreds wounded. The offensive has focused on parts of the capital controlled by a clan that is a supporter of more radical elements of the Council of Islamic Courts, which ruled Mogadishu for six months before being driven out in December. That clan is the Habr Gedir, a branch of the larger Hawiye clan.

The International Committee of the Red Cross said dozens of people have been killed since Thursday and more than 220 wounded, most of them civilians with bullet, grenade, and other wounds. But the fighting is so severe and widespread that bodies were not being picked up or even tallied. Hospitals were overwhelmed, with patients sleeping on floors.