He added that each of them has already appeared before the local courts for the preliminary hearings and now criminal charges are being prepared.

The capital of Benishangul Gumuz, Assosa, as well as surrounding areas, were scenes of violent ethnic clashes between locals and other resident groups almost three months ago.

The state, located in western Ethiopia along the border with Sudan, is home to the largest national development project: the Grand Ethiopian Renaissance Dam, under construction on the Blue Nile River.