A homemade bomb killed one person and wounded dozens of others in western Cameroon Sunday, an attack the authorities said may have been carried out by anglophone separatists.

The blast came two hours after a parade of school children celebrating Youth Day had passed, state television CRTV reported.

In the town of Nkambe, an "improvised explosive device hidden in a food stall exploded not far from the fairgrounds, two hours after the parade," state television said.

Videos on social media showed children in blue school uniforms running in various directions and people helping wounded victims.

"We have counted 40 wounded, of whom four are serious, and one death," said Adolphe Lele Lafrique, governor of the north-west region.

"The first suspicions are towards the separatists," he told CRTV.

The region has been the scene of bloody fighting between armed independence movements and the army since 2016. That was the year President Paul Biya suppressed protests by the English-speaking minority that feels marginalised in the largely French-speaking country.

Both sides are regularly accused by international rights groups of committing crimes against civilians.

Biya, 90, has run Cameroon almost single-handedly for more than 40 years.