A Christian missionary from Indiana was killed in Cameroon on Tuesday when he was shot while traveling in a region where the military and separatists have been fighting.

Charles Wesco, a 44-year-old Baptist missionary, had been in Cameroon for less than two weeks when he was killed, his sister-in-law, Joy Williams, said.

He was shot in a region of northwest Cameroon where the military has been fighting English-speaking separatists who want to break away from the predominantly Francophone central government and create an independent state called Ambazonia.

The conflict has killed hundreds of people since last year and has emerged as Cameroon President Paul Biya's greatest security problem in nearly four decades in power.

Biya won election to a seventh term earlier this month.

The American missionary was traveling in a vehicle with his wife Stephanie, one of his children and another missionary, Ben Sinclair, heading toward the town of Bamenda, when he was shot in the head.

Another Cameroon missionary, Rebecca Sykes Sinclair, posted on Facebook that Wesco was travelling with her husband Ben, who rushed him to hospital. She said: 'Please pray for the Wesco family as they grieve the loss of their husband/father.'

She said: 'Pray for wisdom in the many decisions that need to be made. Pray ultimately that Charles' death will have an eternal impact here in Cameroon especially. Oh how this country needs Christ!'

Wesco, who lived in Warsaw, Indiana, and belonged to a local Baptist church there, had been a piano tuner before becoming a missionary, said Joy Williams. He is survived by eight children.

The Wesco family had originally planned to move to Cameroon in August but had delayed their mission because of the unrest, she said, adding that 'They were aware of the danger.'

On his Cameroon4God website, Wesco had written about his growing sense of call to the region. 'In the Fall of 2014, the Lord began to intensify in our hearts a burden and calling to the Continent of Africa,' he said. 'I had been on several previous missions trips to Africa before we were married, and already had left a part of my heart there. My wife also had always felt a strong burden for missions. As we prayed and sought as to where the Lord would have us to serve Him next, He began to open many doors for the country of Cameroon. During our survey trip in the Spring of 2015, the Lord deepened our love and burden for the people of Cameroon, who are so needy and so open to the Gospel of Jesus Christ!'

Wesco's brother Tim serves in the Indiana House of Representatives. Indiana's Governor Eric Holcomb said in a statement: 'Janet and I are thinking of Rep. Tim Wesco and his family as they grieve the death of his brother Charles. We ask that all Hoosiers join us in offering prayers and condolences to the Wesco family.'

Additional reporting by Reuters.