An armed group in Ethiopia's restive Oromia region has carried out a "horrendous" attack on civilians, the government says, with one survivor saying dozens had died.
The incident is likely to further ramp up pressure on Prime Minister Abiy Ahmed, winner of last year's Nobel Peace Prize, to improve security in a country struggling with grisly ethnic violence.
The killings were carried out on Sunday by an armed group called OLF Shane in the Western Wollega Zone of Oromia region, administrator Elias Umeta told Reuters.
"We buried today 32 of them. About 700 to 750 people were also displaced from the area," he said.
OLF Shane split from the Oromo Liberation Front (OLF), an opposition party that spent years in exile but was allowed to return to Ethiopia after Prime Minister Abiy Ahmed took office in 2018.
Sporadic violence has rocked Ethiopia since then.
OLF Shane says it is fighting for the right of the Oromos, the largest ethnic group in Ethiopia. But there was no immediate known motive for the killings, Umeta said.
"They were executed after they were told by the armed group they want to have a meeting with them," he said.
A survivor who spoke by phone to AFP said the violence erupted after soldiers stationed in the area abruptly and inexplicably left, allowing OLA fighters to round up civilians.
"After collecting us, they opened fire on us, and then afterwards looted cattle and burnt down houses," said the survivor, who spoke on condition of anonymity for safety reasons.
"I have counted more than 50 corpses, and I know there were others hit by bullets," the survivor said.
The OLA, believed to number in the low thousands, broke off from the Oromo Liberation Front (OLF), an opposition party that spent years in exile but was allowed to return to Ethiopia after Abiy took office in 2018.
Abiy's government has blamed it for a spate of assassinations, bombings, bank robberies and kidnappings in Oromia.
The National Movement of Amhara (NAMA), an opposition party, said the perpetrators of Sunday's attack appeared to have targeted members of the Amhara ethnic group, Ethiopia's second-largest.
Authorities last week barred NAMA from staging demonstrations denouncing violence against the group.
Separate attacks on Amhara civilians have recently been reported in two other regions.
Dessalegn Chanie, a senior member of NAMA, said Monday that "up to 200 Amharas were ruthlessly murdered" in Sunday's attack, though he acknowledged the precise toll was difficult to pin down.
"According to survivors from the area whom I talked to earlier today, they are not sure about the count of deaths because they just ran" into the forest, he said.
Oromia regional officials did not respond to multiple requests Monday seeking further comment.