At least 40 regional government officials in Ethiopia's western state of Benishangul-Gumuz have been sacked following a wave of ethnic-related violence, the ruling Prosperity Party (PP) has said.

Ten of the officials are now under investigation, it added, without giving further details.

Five districts in the state have been put under military control to contain the violence that left dozens dead and hundreds displaced last week.

The government-linked Ethiopian Human Rights Commission said it was deeply alarmed by the violence, which targeted civilians.

In a pre-dawn attack on Friday, at least 15 people, including four women, were killed. Attacks earlier in the month left 30 people dead, although activists say the number could be as high as 80.

Most of the victims in the attacks were said to be from the Amhara and Agew ethnic groups.

It is not clear who the perpetrators were.

On Sunday, the authorities from Amhara state accused officials in Benishangul-Gumuz of not doing enough to prevent the violence.

The Amhara state spokesperson added that his region’s government was "running out of patience".

There is concern about the increasing ethnic-related violence in Ethiopia. It is seen as one of the most pressing challenges for Prime Minister and Nobel Peace Prize winner Abiy Ahmed.