At least 750 civilians were killed in the northern Afar and Amhara regions in the second half of last year, Ethiopia's human rights body says.
More than half died in air strikes and heavy artillery fire, it said. The rest died in extra-judicial killings.
It said fighters from neighbouring Tigray tortured and raped civilians. More than 4,000 schools have been damaged or destroyed and around 2,400 health facilities have stopped working due to war damage.
War erupted in Tigray 16 months ago and spread to the neighbouring regions of Afar and Amhara.