The Ogaden National Liberation Front (ONLF) wants autonomy for the ethnic Somali-dominated province, which is drawing interest from foreign firms who think its deserts might hold significant oil and gas deposits.
The group said in a statement that hundreds of civilians were tortured by government troops in November after they were displaced from their localities.
“A brigade has engaged the Ethiopian Army on multiple fronts around Degahbur from November 23 to 25. They lost 35 soldiers in the operation, with many wounded,” the ONLF said.
“This operation was to disrupt the Ethiopian government’s new strategy of evicting people from their habitat and confiscating their properties, then taking them to killing centres,” the group said.
Government spokesman Shimelis Kemal dismissed the claim.
“What happened was that the army was conducting a mop-up operation to get rid of bandits. Six of their members were killed while two were captured,” he told Reuters by phone.
Ethiopia says the Ogaden basin may contain gas reserves of 4 trillion cubic feet and major oil deposits.
The ONLF routinely claims victories over the army. The government has admitted to small skirmishes in the past year but Prime Minister Meles Zenawi said the ONLF had been defeated.
Ethiopia signed a peace deal in October with a faction of the ONLF, although another division of the group called the deal “irrelevant”.
“They (ONLF) have been crushed. This is a splinter group that is limited to highway robberies and nothing more,” Shimelis said. Addis Ababa says the ONLF are “terrorists” supported by regional rival Eritrea.