At least 17 people were killed by security forces in English speaking part of Cameroon on Sunday following protests there, Amnesty International reports.
The protesters are demanding independence from the Central African country.
Cameroonian authorities had blocked the internet in that part of the country for three months earlier in the year following similar protests.
“The worrying escalation witnessed over the weekend has now reached a crisis point,” Ilaria Allegrozzi, Amnesty International’s Lake Chad researcher said:
“The use of excessive force to silence protests in the West and South-West regions of Cameroon is not the solution.
“All deaths related to these protests must be promptly and effectively investigated.”
While President Paul Biya has condemned the violence and called for dialogue, scores of protesters remain in detention.