NAIROBI, Kenya (AP) — An Ethiopian news agency says several dozen people have been killed in the latest massacre along ethnic lines in the western part of the country.

The Amhara Mass Media Agency, affiliated with the country’s Amhara region, cites witnesses as saying the attack occurred early Wednesday morning in the Metekel zone of the Benishangul-Gumuz region.

The attack occurred a day after Prime Minister Abiy Ahmed visited the region and spoke about the need to bring those responsible for recent attacks to justice. Ethnic tensions are a major challenge as Abiy tries to promote national unity in a country with more than 80 ethnic groups.

The witnesses, speaking by phone, said houses were burned in the attack in Bikuji county.

It was not immediately clear who the attackers were. The ruling party in the region, the Benishangul-Gumuz Prosperity Party, said in a statement that “armed bandits” had committed a “horrifying crime.”

Amharas are the second most populous ethnic group in Ethiopia. Amharas in the region have been targeted repeatedly in recent weeks.

One rebel attack on Nov. 1 in the far western Oromia region killed at least 54 people, according to Amnesty International.

An attack in the Benishangul-Gumuz region in early October killed at least 14 civilians, according to a security official. It followed similar deadly attacks in September that also displaced over 300 people, leading the Ethiopian Human Rights Commission to say it was deeply alarmed.