Government soldiers are seen on patrol in Bafut, in this file photo, taken on November 15, 2017, in the restive northwest English-speaking region of Cameroon. AFP
The church of St Mary in the village of Nchang was "burned by unknown armed men" in the attack on Friday, the Bamenda Provincial Episcopal Conference said.
"It was with great shock and utter horror that we, the Bishops (of the BAPEC) learnt of the burning down of the St Mary's Catholic Church, Nchang... and the kidnapping of five priests, one religious sister and two lay faithful by unknown gunmen," the statement said.
"This act was completely unprecedented and, as of now, no concrete reason has been given for this heinous act against the house of God and the messengers of God".
The attack has not yet been claimed, but they are often perpetrated by separatist groups and result in hostages being released after ransom demands or negotiations with local leaders.
The North West and South West regions of Cameroon have suffered a bloody conflict between anglophone separatists and the state for years.
English speakers make up a majority of the regions' populations in predominantly French-speaking Cameroon, which President Paul Biya has ruled with an iron fist since 1982.
Anglophone resentment at perceived discrimination snowballed into the declaration of an independent state in 2017 -- the "Federal Republic of Ambazonia" -- an entity that is not recognised internationally.
Biya, 89, has resisted calls for more autonomy in the regions and responded with a crackdown on the separatists.
The violence has claimed more than 6,000 lives and displaced around a million people, according to the International Crisis Group (ICG) think tank.
International monitors and the United Nations say both sides have committed abuses, including crimes against civilians.
Last week, six people were killed in an attack on a bus in the country's western region.