The fertile border areas of Chad, Cameroon and Central African Republic have been gripped by confrontation between predominantly Muslim nomadic herders and sedentary farmers who are typically Christian or animist.
Tensions are historically rooted in rivalry over land.
The farmers often accuse the herders of letting their cattle trample their crops and eat them, while the herders say they have the traditional right to graze there.
The latest outbreak of violence occurred on Thursday, when a 12-year-old herder took his animals onto a farmer's peanut field, leading to an altercation that left the child dead, Adoum Forteye Amadou, the governor of the Madoul region, told reporters.
His parents then killed nine farmers in revenge, Amadou said, adding that the incident occurred near the village of Bara II, 600 kilometres southeast of the capital of N'Djamena.
"Five herders, the authors of the killing spree, have been arrested, as well as the murderer of the young herder," he said.