Several people have been shot dead by security forces during protests in Cameroon, Amnesty International said.
The group said some demonstrations had turned violent in Cameroon's English-speaking regions on Sunday as people gathered on the 56th anniversary of the incorporation of those areas.
Amnesty also expressed worry over the government's "ongoing campaign to silence any form of dissent in the West and South-West regions of Cameroon".
On Friday, the north-west province banned meetings and travel for 72 hours.
The rights group called on security forces to cease unnecessary violence and urged protesters to be peaceful.
Cameroon has areas which were colonies of France and Britain until the early 1960s.
The West African country's English-speaking population started protests last year against alleged discrimination by the majority French-speaking population.