Seven people including a senior Cameroon government administrator and a mayor were killed in an ambush that involved an improvised explosive device (IED) on Wednesday in the country’s restive southwest, the region’s governor said.

Bernard Okalia Bilai, Governor of the South West Region, said the Sub-prefect of Ekondo Titi was on a tour of his jurisdiction when his convoy hit an IED, and was then attacked by separatist fighters.

“It was a terrorist attack. It was an ambush,” Bilai told journalists, adding that the situation was under control.

The region is one of two English-speaking regions in the Central African nation, where insurgents are seeking to form a breakaway state called Ambazonia.

They began fighting the military in 2017 after civilian protests calling for greater representation for the country’s English-speaking minority were violently repressed.

The administrator is the highest government official to be killed so far in the conflict that has claimed over 3,000 lives and displaced nearly one million.

Cho Ayaba, who leads the Ambazonian Defence Force, one of the main English-speaking separatist groups, claimed responsibility for the attack on Twitter.