Ethnic violence has been a persistent problem in Ethiopia under Abiy, winner of last year's Nobel Peace Prize
Twelve people were killed this week in Ethiopia's western Benishangul-Gumuz region, a security official said, the latest in a series of clashes there that opposition politicians describe as ethnically motivated.
The killings in the region's Metekel zone began early Monday and were sparked by a "personal dispute" over a stolen firearm, Gashu Dugaz, head of the region's security bureau, told the state-affiliated Fana Broadcasting Corporate.
But Dessalegn Chanie, an opposition politician in the neighbouring Amhara region, said the incident was a "gruesome" attack on members of the Amhara ethnic group, the country's second-largest.
Dessalegn, a senior member of the National Movement of Amhara political party, told AFP Tuesday that up to 40 people could have died, a figure that could not be independently verified.
Dessalegn and other Amhara politicians and activists have for weeks been sounding the alarm about what they say is a targeted campaign by ethnic Gumuz militias against ethnic Amhara and Agew living in Metekel zone.
The government of Prime Minister Abiy Ahmed has provided scant details about the violence.
Abiy's press secretary Billene Seyoum said at a press conference in late September that the government "condemns all violent acts that are causing civilian casualties harm and destruction" and said some 300 people "including leadership in the area" had been "apprehended for their involvement."
When asked what was driving the violence, Billene said investigations were ongoing.
"There is some information to indicate that bandits are operating in the area as well," she added, without providing details.
Ethnic violence has been a persistent problem in Ethiopia under Abiy, winner of last year's Nobel Peace Prize.
The independent Ethiopian Human Rights Commission reported that 15 civilians were killed in Metekel zone on September 25 and said the violence was an example of "targeted killings."
"Civilians are being subjected to repeated attacks with unmitigated cruelty in Benishangul-Gumuz," Daniel Bekele, the body's chief commissioner, said at the time.
"Federal and regional authorities should take the required steps to enforce the rule of law and bring perpetrators to account," he said.
Ethiopia's military is reinforcing police and other security forces as they try to stabilize the area, Fana reported this week.