Clashes between two Ethiopian states that have long disputed their border have killed at least 27 people, a government statement said, as the country faces surging ethnic violence.

The 27 were killed “due to conflicts along the borders of Somali and Afar”, the statement said. Militias from the two eastern states have clashed before over their disputed boundaries.

Ali Bedel, a spokesman for the Somali region, confirmed the killings and blamed militants in Afar.

“Local militias from Afar were behind the killings,” he said.

A spokesman for the Afar region did not respond to a Reuters call for comment.

In 2014, the federal government redrew the boundary between the two states and transferred three small towns to Afar that Somali has since wanted back.

“The transfer of three Somali towns to Afar regional administration in 2014 without any legal procedure lies at the heart of these recurring tragic and senseless killings,” Mohamed Olad, a political analyst based in Addis Ababa, told Reuters.

Deadly intermittent unrest has rocked Ethiopia since Prime Minister Abiy Ahmed came to power in 2018.

Africa’s second most populous nation, Ethiopia is one of the continent’s fastest growing economies and is due to hold elections next year.

But decades of frustration over government repression and a series of democratic reforms by Abiy have emboldened regional power-brokers keen to challenge the ruling party.

Long-suppressed frustrations frequently explode into ethnic violence.