Boko Haram terrorist activity spreading into Cameroon from northeastern Nigeria has caused local Catholic missionaries to increase security, but one bishop has stressed that relations with local Muslims are good.

"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," Bishop Bruno Ateba of Maroua-Mokolo told Christian charity Aid to the Church in Need Sept. 30.

He said armed soldiers now accompany missionary priests when they celebrate Sunday Mass.

"It's the Boko Haram extremists who come to us from Nigeria and cause disruption; apart from that we have no problems with Muslims," he said.

Boko Haram has killed thousands since its insurgency began in 2009. The militant Islamist group is blamed for least 2,000 deaths in 2014 alone. The U.N. estimates their attacks have created more than 470,000 internally displaced persons, in addition to some 57,000 refugees outside of the country.

The terrorist group has made highly publicized attacks in Nigeria, including the April abductions of hundreds of schoolgirls.

However, the group has also been active in Cameroon. From late 2013 to April 2014, militants with the group have abducted a French priest, two Italian priests, and a Canadian nun in the country. They were all released within a few weeks of their abduction.

Bishop Ateba speculated that the missionaries' governments may have paid a ransom for their release.

The bishop's diocese is in Cameroon's north and encompasses the country's Far North province. The diocese borders northeast Nigeria, where Boko Haram has been expanding.

About half of the 3 million people in Cameroon's Far North province are Christian, and Catholics comprise 25 percent of the total population. Another 25 percent are Muslim.

The bishop said there is a "strong dialogue" with local Muslims, and Catholics and Muslims "regularly exchange views."

The Maroua-Mokolo diocese has 43 parishes served by 73 priests. The diocese is heavily reliant on foreign priests, with only 23 priests being from Cameroon. In addition, About 100 women religious provide pastoral care and run charitable institutions, Aid to the Church in Need reports.

Bishop Ateba, who has headed his diocese since May, said his diocese is "a missionary area."

"That's why there are so many missionaries and religious priests working with us," said the bishop, who is himself a member of the Pallottine apostolic society.

He said the diocese has difficulty meeting its material needs.

"We lack a lot of things. In Maroua we also have a small church, but we want to build a cathedral soon so that we do not have to conduct services in the open air," he said.