Fierce fighting between heavily armed rival clans in war-torn Somalia has killed at least 26 people in a dispute over grazing land and water, officials said Sunday.

"There are many casualties, the initial reports are of 26 people killed," said Mohamed Abdi Shire, a senior commander of the Ahlu Sunna militia in central Somalia, which controls the region. Clashes broke out Saturday in the central Galgadud region, around the villages of of Marer and Balalder, he added.