At least 196 people were killed during ethnic clashes in Ethiopia's Gambella region at the end of January, according to a government report.
It said that fighters from the Anyuak community had launched an attack, killing mainly traditional miners.
Aid agencies say the fighting is between the local Anyuak and highlanders from outside the area.
Tension in the area has been high since a riot in Gambella in December which left dozens of Anyuak dead.
The government statement said more than 200 fighters had committed "atrocities" in the Dima district of Gambella to avenge the riot deaths.
It said that of the 196 killed, 172 were traditional
miners "mainly from the Southern Nations, Nationalities and Peoples state".
On the December riot, the government put the number of Anyuak killed at 60 but the Ethiopian Human Rights Council says the actual toll is closer to 300.
It was not clear on Wednesday what tribal affiliation the new victims had.
The renewed fighting in western Ethiopia has also sparked international concern.
UK Secretary for International Development Hilary Benn, who is touring Ethiopia, voiced "great concern" about the violence.
Aid agencies working in the area say an estimated 15,000 Anyuak tribesmen have fled the violence into neighbouring Sudan.