Clashes sparked by a cattle-rustling incident in the Marsabit district of northern Kenya have left about 15 people dead and displaced hundreds more in the past week, aid workers said.

Fighting between the Gabra and Turkana communities erupted on 8 May when members of one group raided villages inhabited by the other and stole about 1,000 cattle, sheep and goats, prompting revenge attacks by the livestock owners.

An estimated 1,000 people have fled Moite and Komote villages in the Loyangalani division of Marsabit, the scene of the clashes, according to David Timado, a social worker and peace activist in the area, which is mainly inhabited by livestock-herding communities and has a history of ethnic animosity caused by competition for pasture land and water.

"The situation in Loyangalani is bad. Tension is high and residents are leaving," said Timado. "So far, many people, almost 1,000, have moved away, walking long distances," he said. Some of the displaced families from the affected villages had arrived in Loyangalani trading centre, about 100km away, after walking for more than two days with little food and water, he added.

Families were still fleeing, despite the deployment of more police officers in the affected area.

The Kenya Red Cross Society's disaster management office in Marsabit said it had registered 27 displaced families. The officer in charge, Ahmed Mohamed, said those registered had already received food rations and shelter material. "We have given food and tents to those displaced, many of whom ran away without food and only took a few belongings," he said.

Local police said 11 civilians and four raiders had died in the violence.