Clashes between rival groups in Sudan's Darfur killed at least 168 people on Sunday, an aid group said, in the latest bout of deadly violence to hit the restive region.
Darfur, which was ravaged by civil war that erupted in 2003, has seen a spike in deadly conflict since October last year triggered by disputes mainly over land, livestock and access to water and grazing.
The latest fighting erupted on Friday in the Krink region of West Darfur, said Adam Regal, spokesman for the General Coordination for Refugees and Displaced in Darfur, an independent aid group.
"At least 168 people were killed on Sunday and 98 wounded," said Regal, voicing fears that the death toll could rise.
The violence broke out when armed tribesmen attacked villages of the non-Arab Massalit minority in retaliation for the killing of two tribesmen, AFP quoted the aid group as saying.
At least eight people were killed on Friday, it added.
On Sunday, a tribal leader from the Massalit minority described seeing multiple bodies in villages of the Krink region, which lies some 80 kilometers (50 miles) from West Darfur's provincial capital, Geneina.
Medics from the Central Committee of Sudan Doctors warned of "catastrophic" health conditions in West Darfur, saying that several hospitals were attacked in the violence.
The International Committee of the Red Cross called on authorities to ensure the safe arrival of the wounded to hospitals.
The United Nations special representative Volker Perthes condemned the killings and called for a probe.