It was not immediately clear what caused the violence, which has largely been restricted to the region’s capital, Assosa, although residents said that large mobs were attacking racial minorities that had settled there.

People of Berta and Gumuz descent are the indigenous inhabitants of Benishangul-Gumuz, which borders Sudan, but the province has a large presence of Amharas and Oromos, who are labeled “highlanders” and originally hailed from the country’s larger regions of Amhara and Oromia.

Ashadli Hassen, the region’s president, said nine people have died in the violence so far. A day earlier, officials had said only one person was killed.

“We have 40 suspects in custody and we believe they have been given financial incentives to commit violence,” he told reporters on Thursday. He did not give further details.

The violence comes amid increasing race-based unrest throughout the country and after a grenade attack at a rally on Saturday that Prime Minister Abiy Ahmed attended.