Anglophone separatists in Cameroon stripped and "tortured" children at a high school and kidnapped two members of staff, the local prefecture said.

Eight pupils were briefly taken hostage and the two staff members are still missing after separatists attacked the secondary school on Tuesday in western Cameroon, the scene of a bloody conflict between English-speaking independence fighters and the army.

"Armed terrorists attacked the high school," then stripped and "tortured" some pupils, before setting fire to two classrooms and the headmaster's office in the village of Esu in the department of Menchum in the North-West administrative region, the local officials said in a statement.

Cameroon authorities describe as "terrorists" the armed pro-independence groups in the North-West and South-West regions, populated mainly by the English-speaking minority of the vast, mainly French-speaking central African country.

"They kidnapped the headmaster, the general supervisor and eight male students," added the prefecture statement sent to Agence France-Presse on Wednesday.

All the seized students were freed following the intervention of the army on Tuesday.

However, the administration said nothing about the fate of the two members of staff.

A deadly conflict between security forces and pro-independence groups has been ongoing since 2016, with each side regularly accused of crimes against civilians by international non-government organizations and the United Nations.