Clashes between sedentary farmers and semi-nomadic herders in southeastern Chad have left many dead in recent days, humanitarian and human rights sources said Sunday.
The two groups have a long and troubled history in the region, where weapons abound and violence often flares after cattle destroy crops.
The National Human Rights Commission (CNDH) and aid groups said the latest clash claimed more than 100 lives, while the local hospital recorded seven deaths.
"More than 10 villages... were torched and we mourn more than 100 human lives lost," the CNDH said in a statement on Saturday.
The hospital in Am Timan, the capital of Salamat province, meanwhile recorded seven deaths and 61 wounded in clashes in the Mouraya area, a medical source told AFP on Sunday.
Government spokesman Cherif Mahamat Zene told AFP on Friday that calm had been restored.
The CNDH accused the government of failing to anticipate the bloodshed, condemning it for "repeated inaction with regard to such recurring events".
Several aid groups in the capital N'Djamena, some 800 kilometres (500 miles) away, suggested around 100 people died.
Human rights group CTDDH said the clashes erupted after the "suspicious death" of a 21-year-old, pitting ethnic Arabs against Kagals and Kibets between Wednesday and Friday last week.
It said the fighting took place in the villages of Sihep and Ambarit and claimed around 100 lives.
But an Arab tribal leader told AFP on Sunday that 50 ethnic Arabs had died, while an influential Kibet leader in Salamat said 109 Kibets and Kagals were killed.
Thanks to southern Chad's relatively mild climate for the Sahel, its vegetation is lush, and for centuries it has drawn in migratory herders from arid areas, many of them Arabs, for seasonal grazing.