Amnesty International said Eritrean troops systematically killed hundreds of unarmed civilians in Ethiopia’s Tigray region on Friday.

The worst of the fighting took place in the northern city of Axum between November 28 and November 29, with soldiers opening fire in the streets and conducting house-to-house raids.

According to Amnesty International in the new report, this is “a massacre that may amount to a crime against humanity.’’

It said 41 survivors and witnesses and 20 others with knowledge of the events told the researchers.

They gave details of the extrajudicial executions, indiscriminate shelling and widespread looting that took place after Ethiopian and Eritrean troops led an offensive and took control of the city on November 19.

Satellite image analysis has corroborated the reports and shown mass burial sites, according to Amnesty.

“Ethiopian and Eritrean troops carried out multiple war crimes.

“Eritrean troops went on a rampage and systematically killed hundreds of civilians in cold blood,’’ said Amnesty director for East and Southern Africa, Deprose Muchena.

“The Amnesty findings should be taken very seriously,’’ Ethiopian Human Rights Commission (EHRC) chief commissioner, Daniel Bekele, said in response to the report.

While the EHRC had not yet finalised its investigation, its preliminary findings also indicate the killing of an unknown number of civilians by Eritrean soldiers in Axum, Mr. Bekele said in a statement.

The killings were retaliation for an earlier attack by Tigray People’s Liberation Front (TPLF) soldiers joined by a small number of local residents and were carried out by Eritrean soldiers after the TPLF soldiers left the area, according to Bekele.

The commission is also investigating allegations of shelling in multiple places across the Tigray region, Mr. Bekele said.

The commission previously confirmed lootings and sexual violence in Axum and damages to civilian infrastructures in different parts of the Tigray region.

“The full extent of the damages and violations including characterisation of the nature of human rights violations is not yet known since the investigation covers a large area,’’ Bekele said.

Earlier this week, the foundation of South African Nobel Peace Prize laureate, Desmond Tutu, warned the people in the Tigray region are facing “genocide.”

Ethiopia launched a military offensive in Tigray in November to diminish the power of the TPLF, which rules the region and has been critical of the government.

It remains unclear why Eritrean forces might have fought alongside Ethiopia’s army in the Tigray conflict, but there has been long-standing animosity between the TPLF and Eritrea since a 1998-2000 border war.

Eritrea denies its involvement in the Tigray conflict.