NAIROBI, Kenya (AP) — Ethiopian security forces killed more than 75 people and injured nearly 200 during deadly ethnic unrest in June and July following the killing of a popular singer, the Ethiopian Human Rights Commission said Friday.

The commission's report said 123 people in all were killed and at least 500 injured amid one of the country’s worst outbreaks of ethnic violence in years, a “widespread and systematic attack” against civilians that points to crimes against humanity. Some victims were beheaded, tortured or dragged in the streets by attackers.

Ethnic violence is a major challenge for Nobel Peace Prize-winning Prime Minister Abiy Ahmed, who has urged national unity among more than 80 ethnic groups in Africa’s second most populous country.

The unrest in June and July followed the killing of singer Hachalu Hundessa, who had been a prominent voice in the anti-government protests that led to Abiy taking office in 2018 and announcing sweeping political reforms. Those reforms, however, opened the way for long-held ethnic and other grievances to flare.

The commission found that amid the street protests following Hachalu’s death, “civilians were attacked inside their homes by individual and grouped perpetrators and were beaten and killed in streets in a gruesome and cruel manner with sticks, knives, axes, sharp iron bars, stones and electric cables.”

More than 6,000 people were displaced and at least 900 properties looted, burned or vandalized, the report said. The attacks often targeted ethnic Amhara or Orthodox Christians.

“While it is understandable that security forces had the challenging task of restoring order in the face of such widespread violence, the proportionality of the force employed in some contexts is highly questionable,” the report said.

As an example, in several communities, “the commission found that there were people killed with bullet wounds to the head, shots to the chest area or the back. People not participating in the protests — passersby, bystanders observing from their doorsteps, young people, elderly people trying to mediate, people with mental illnesses, and even police officers — also lost their lives.”

In other cases, the commission found that “local authorities and security did not respond to victims’ repeated calls for help, being told instead ‘that higher ups gave no order to intervene’ ... Survivors and witnesses also recount how sometimes police stood watching as the attacks took place.”

Some watchdogs have warned of a return to repressive measures in Ethiopia as authorities grapple with hate speech and ethnic violence.

The unrest was not related to the conflict in Ethiopia’s northern Tigray region that began in early November, but it was another sign of the tensions straining the country of some 110 million people at the heart of the Horn of Africa.

A spokeswoman for Abiy’s office did not immediately comment on the report, and the commission did not say what the government's response had been. Interviews with government officials and security figures were part of the commission’s investigation, which also involved visiting some 40 communities.

The commission said it found no indication of “ongoing efforts to investigate the use of force by security officers during the unrest and to hold to account those who caused unnecessary human suffering.”

The report noted that “crimes against humanity of this nature combined with the current national context are signs that the risk of atrocity crimes, including genocide, is increasing,” and it called for investigations, justice and “a lasting and institutional solution for the increasing trend of discrimination and attacks against minorities.”