Armed men killed more than a hundred people in a dawn assault in the western Benishangul-Gumuz region of Ethiopia, Reuters reported Thursday.

The Ethiopian Human Rights Commission, an independent government-linked body, said in a statement Wednesday that survivors had "disturbing photo evidence of the dawn attack" on sleeping residents in the Metekel zone.

The killings that took place between 4 a.m. and midday Wednesday following the pullout of government security forces, the commission said. It called for an immediate investigation and prosecution of those behind the attack.

It said at least 36 others were receiving medical care for arrow and gun injuries in a hospital in Bulen, roughly 90 kilometers from where the attack occurred.

Africa's second-most populated nation has been struggling with consistent outbreaks of violence since Prime Minister Abiy Ahmed took office in 2018 and fast-track democratic reforms that eased the government's control on regional contention.

Ahmed's unbanning of opposition and insurgent organizations has triggered political disintegration and long-subdued rivalries among ethnic inhabitants.

The commission said no police or security force was stationed in the area at the time of the attack, although army personnel were deployed to the area Dec. 22 to appease tensions but had left soon after.

A violent seven weeks in the Tigray region has displaced thousands and claimed the lives of an undetermined number of civilians.

Elections set next year have stirred up tensions over land ownership and control, resources and power in the region.

The country is battling rebel groups in the Oromiya region and faces security threats from Somali militants along its open eastern border.