The latest clashes between the Borana and Gabra communities, which follow weeks of unrest in December, began on 3 January and continued into the following day.
The fighting reportedly broke out after a disagreement between youths at a peace meeting degenerated first into an exchange of stones, then gunfire.
The Kenya Red Cross Society said six people had so far been confirmed dead, three of them children, and dozens of houses had been burnt. Three other people were reported to have sustained serious injuries.
Difficulties in accessing the affected villages of Odha, Kanisa, Masille, Iladu and Hellu led officials to believe the final toll could rise significantly,
Some 1,700 children from these villages have been unable to attend school because they fled with their families to Moyale town, according to one education official.
Reacting to complaints of government inaction, Regional Commissioner Issah Nakoru said: “Our people must be assured that the government has deployed more than 1,000 security officers in Moyale and Isiolo [about 500km to the southwest].”
Residents “have a role to play. Tell us those who among them are engaged in the fight and those who are inciting the communities to fight,” he said.