Four people, including three civilians and an Ambazonia fighter, were killed as violence escalated in Southern Cameroons, security sources said Sunday.

 Ambazonia Restoration Forces opened fire on a vehicle on a highway in Ekona, a locality in the Southwest Region, on Saturday, killing the driver and two passengers, a security official in the region said.

“They were driving to Kumba when the Amba forces killed them. The Southern Cameroons liberation force said they disrespected a lockdown order,” a pro Yaoundé government official reportedly said and sued for anonymity.

Government forces pursued the fighters after the shooting, leading to a clash that left one separatist fighter dead and several others injured, the official said.

Fighting has intensified in the English-speaking Northwest and Southwest regions since Monday, after separatists declared a week-long lockdown to disrupt the reopening of schools.

Separatist groups have been clashing with government forces since 2017 in a bid to create an independent state in the two regions.

By Rita Akana with files