Police in Ethiopia say they have discovered a mass grave with 200 bodies near the border between Somalia and the country's Oremia.
Hundreds of thousands of people have been displaced in the past year by violence there.
The local media reported that the tomb was found during an investigation into alleged violence by the former Ethiopian President in Somalia.
Abdi Mohammed waits trial for allegations that sparked ethnic clashes.
A notorious regional security force known as Liyu police is accused of carrying out murders in the region between Somalia and Oromia and reported directly to the regional president.
The police are trying to locate the 200 bodies found.
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Mr Mohammed was forced to resign in August and was arrested weeks later after the outbreak of violence in the regional capital, Jijiga.
It is considered to have supervised extensive violations of rights, including torture, rape and murder, during its ten-year rule.
Last month, the state-run broadcaster Fana reported that he tried to escape the police custody by going up a window in front of the appearance of the court.