The latest HRW report said these killings highlighted the urgent need for the United Nations Human Rights Council (UNHRC) to establish an international investigative mechanism into abuses by all warring parties in the expanded Tigray conflict.

Tigrayan forces on Aug 31 had entered the village of Chenna and engaged in sporadic and at times heavy fighting with Ethiopian federal forces and allied Amhara militias, the report said.

HRW reported quoting Chenna village residents that over the next five days Tigrayan forces summarily executed at least 26 civilians in 15 separate incidents, before withdrawing on Sept 4.

Meanwhile, on Sept 9, Tigrayan forces summarily executed a total of 23 people in four separate incidents in the town of Kobo, reports HRW, citing witnesses.

According to the report, the killings were in apparent retaliation for attacks by farmers on advancing Tigrayan forces earlier that day.

Caption: File photo of a village in Ethiopia's Amhara region, by Ji Elle via Wikimedia Creative Commons

Lama Fakih, the crisis and conflict director at Human Rights Watch, said, "Tigrayan forces showed brutal disregard for human life and the laws of war by executing people in their custody.”

“These killings and other atrocities by all sides to the conflict underscore the need for an independent international inquiry into alleged war crimes in Ethiopia’s Tigray and Amhara regions,” Fakih added.

Since the beginning of the armed conflict in Ethiopia’s northern Tigray region in November last year, Ethiopian military forces, alongside Eritrean armed forces, Amhara regional special forces, and Amhara militias, have fought against a Tigrayan armed group affiliated with the region’s former ruling party, the Tigray People’s Liberation Front (TPLF).

In July this year, fighting expanded to the neighboring Amhara region, leading to large-scale displacement, with 3.7 million people in the region in need of humanitarian assistance, according to the report.

"Tigrayan forces put civilians at grave risk by holding them in residential compounds and shooting from those compounds at Ethiopian troops positioned on nearby hills, drawing return fire," reports HRW, quoting witnesses, adding that "such actions may amount to 'human shielding', a war crime."