At least 20 people were killed, 50 wounded and hundreds more displaced during inter-clan fighting that began on Monday in the town of Beletweyne in south-central Somalia.
The fighting broke out on Monday at around 5:00 p.m. [02:00 GMT] when militias from the Galje'el and Jajele sub-clans clashed on the west side of the town, local journalist Abdullahi Muhammad told IRIN on Tuesday.
He said the conflict subsided a few hours later but "restarted on Tuesday morning with both sides using heavy weapons".
Since Monday, families have been fleeing to the relative safety of Beletweyne's surrounding villages.
"Those who remained, hoping the fighting would die down, are now leaving in droves," Abdullahi said.
The fighting was reportedly triggered by a land dispute and revenge killings for the deaths of two Jajele men last week and one Galj'el man on Sunday.
However, the ensuing escalation of violence has been attributed to other disagreements.
"Unfortunately, this is something that happens when nomads in search of pasture and water collide with each other," Abdullahi said.
He added that the death toll could rise once the fighting had stopped and both sides could take the wounded to hospital.
Meanwhile, mediation efforts are underway to resolve the conflict. A 25-member committee comprising elders, religious leaders and scholars from a neutral clan has been set up, Hassan Ilmi Hure, an elder and a member of the committee, told IRIN.
"We are trying as a first step to get a ceasefire," he said. The committee had established contact with both sides and hoped to achieve a ceasefire by Tuesday.
"Once we have a ceasefire we will then deal with the core issue of the land dispute," Hure said.
Beletweyne, 330 km north of Mogadishu, is the capital of the Hiiraan region, which has recently been devastated by rain-induced floods. About 5,000 families in and around the town have been displaced and 2,500 ha of farmland inundated.