Christians are a minority population in Muslim dominated N W African countries such as Nigeria, Mali, Burkina Faso, Niger, Chad and Sudan. These Christians belong to Orthodox Christian Churches that began very early after the Good News was preached by the original disciples.
It is sad that followers of Islam cannot tolerate any religious minorities to live and worship within their lands. The governments there say all are to be protected but do not offer protection in fact. France and our US have sent troops to advise and help the listed governments but the killings continue.
Actually, I believe that Nigeria is 50/50 Christian and Muslim.