Authorities in Cameroon said five soldiers and a civilian were killed early Wednesday in the troubled English-speaking region of Northwest when an improvised explosive device hit their vehicle.

The soldiers were part of a government convoy that had travelled to the remote sub-divisions of Njikwa and Ngie to install newly appointed sub-prefects.

The blast occurred when they were returning from the installation ceremony, according to Northwest regional chief of communication, Louis Marie.

The civilian killed was a government official. "They were killed by terrorists," Marie said referring to armed separatists who are known to be operating in the area.

Separatists have been clashing with government forces since 2017 in a bid to create an independent nation in Cameroon's two English-speaking regions of Northwest and Southwest.