The area is the fault line between Islamic Africa to the north and predominantly Christian Africa to the south.
Open Doors, the Christian freedom charity say general violence has increased because of a mix of poverty, unemployment, corruption and lack of governance.
However, for Christians, they have seen increasing Islamic extremism in the area as it becomes a hotspot for Islamic militant groups, some being home-grown and others being part of international terror organisations like IS and Al-Qaeda, as members often settle in states along the Sahel when they are driven out of the Middle East.
Open Doors say these ideologies are gaining popularity because they come with the provision of goods and services which the state has failed to provide and they are promising a new political order free from corruption.
Almost 30 violent Islamist groups are known to be active in the region with most committing attacks in more than one country. For example, Boko Haram has spread out from north Nigeria, across Lake Chad and into other countries.
Their ideology has infiltrated numerous splinter groups such as Islamic State West Africa Province, a group which broke away from Nigeria's Boko Haram and targets and enslaves Christian women and girls.
At least six churches in the DRC have been burned down and two church-run clinics and health centres have been destroyed. In Mali, witnesses reported that over 100 Christians were killed but the official figures quote 35.
Many militant Islamic groups view the sparsely populated land of the Sahel as a safe haven as states have only nominal sovereignty and so they have established bases there.
Henrietta Blyth, CEO of Open Doors UK and Ireland said: "The situation for Christians in the Sahel is precarious; this is a critical time for the future of Christianity in the region. If the militant groups have their way, Christians and Muslims who do not subscribe to their ideology will be killed and driven out of the entire region."
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.