US scientists say satellite images confirm reports that the Ethiopian military have burnt towns and villages in Ethiopia's Somali region.
The American Association for the Advancement of Science says the images back up a Human Rights Watch's report
The US-based group says the troops are systematically ill-treating civilians in their counter-insurgency campaign.
Ethnic Somali rebels have been fighting for more autonomy for two decades in the region, also known as the Ogaden.
HRW also accused the United States and the European Union of ignoring widespread abuses there.
The Ethiopia government has described the report as "unfounded and baseless".
HRW cites evidence of extrajudicial detentions and killings, beatings and rapes in military custody, forced displacement of the rural population and the collective punishment of communities suspected of helping or sympathising with the Ogaden National Liberation Front (ONLF) rebels.
"We found that over the last year the Ethiopian army has been killing, raping, torturing and systematically displacing civilians in the Ogaden region of Ethiopia," HRW's Georgette Gagnon told the BBC's Network Africa programme.
She said there was no doubt about the identity of those carrying out the abuses.
"All the victims and eyewitnesses that we interviewed clearly identified the Ethiopian army and soldiers as those who had raped them, for example, who had summarily killed people by strangling, and who had forcibly displaced them and burned their villages."
According to the AAAS, eight "before" and "after" satellite images identified by HRW as possible locations of abuses bore signs of attacks described.
These were primarily in villages and small towns in the Wardheer, Dhagabur, and Qorrahey Zones, the AAAS said.
One recurrent scenario was of the army's response to ONLF activity in a neighbourhood; they would call the inhabitants together and demand that they hand over the culprits, HRW says.
Failure to do so resulted in village elders and others being arrested, beaten, sometimes killed.
Young people, both boys and girls, were arbitrarily arrested and accused of being ONLF sympathisers; they were routinely beaten in custody and women often raped, HRW says.
The apparently arbitrary nature of many of the arrests was explained to HRW by a former judge in the region who said the army could not tell the difference between rebels and civilians, he said they were confused as to who was who.
The report concludes that the army is engaged in a deliberate policy of terrorising the local population; that the abuses are far too systematic and widespread to be considered simply the acts of rogue commanders.
But Bereket Simon, special adviser to Ethiopia's prime minister, said that HRW had based its findings on ONLF propaganda.
"Human Rights Watch is engaged in misinforming the public based on the information of the ONLF, whose forces have been destroyed by the actions of the Ethiopian government," he told AFP news agency.