Recent months have seen several attacks on churches by Boko Haram militants, and thousands of Christians are being persecuted.
The terrorist group is trying to create a state that is run under strict Muslim law.
Bishop Bruno Ateba of Maroua-Mokolo, in the north of Cameroon, spoke to Aid to the Church in Need.
He said: "Following Boko Haram's abduction of three priests and a nun in the border region by Boko Haram, missionaries are now accompanied by armed soldiers when they celebrate Sunday Mass there.
"It's the Boko Haram extremists who come to us from Nigeria and cause disruption; apart from that we have no problems with Muslims. Rather, there is a strong dialogue since we regularly exchange views.
"The Boko Haram fighters supply themselves with food in the border area and attempt to make money by kidnapping. That's why the priests and nuns are now accompanied by the military when they visit the parishes close to the border."
One French and two Italian missionary priests, as well as a Canadian nun, were abducted between late 2013 and April 2014, but they were all were released after a few weeks. It is thought a ransom may have been paid.
John Pontifex from Aid to the Church in Need spoke to Premier about the situation and appealed for prayers: