Amnesty International says Eritrean troops have killed three people and injured at least 19 others during an unprovoked attack on civilians in Ethiopia.

Witnesses told Amnesty that the soldiers were passing through Adwa in the Tigray region on Monday when they suddenly opened fire on people near the town’s bus station.

They said Eritrean soldiers were shooting from the back of military trucks.

Amnesty is calling for an international investigation into this and other human rights violations during the almost six months of conflict in Tigray.

Last month Ethiopia’s Prime Minister, Abiy Ahmed, acknowledged that troops from Eritrea were fighting in the Tigray region. For months both countries had denied their involvement in the war.

The Ethiopian government has not responded to the latest allegations.