Cameroon authorities have regularly tortured and held incommunicado detainees arrested in the government's crackdown on an English-speaking armed separatist movement, Human Rights Watch (HRW) said Monday.
The New York-based rights group in a report urged the United Nations to put Cameroon's situation on its agenda and to condemn abuses against people arrested on suspicion of having ties to separatists.
Since 2017, fighting between government troops and anglophone separatists demanding independence in the southwest and northwest regions has killed hundreds and forced nearly 500,000 people from their homes.
English-language communities chafe at what they see as discrimination from the French-speaking majority. But the government rejects demands for autonomy and has dispatched thousands of troops in a crackdown.
Human Rights Watch said it had documented 26 cases of incommunicado detention and enforced disappearance between January 2018 and January 2019 at the State Defence Secretariat (SED) detention centre in the capital Yaounde.
It said security forces at SED had "severely beaten and used near-drowning to extract confessions from detainees."
"Over the past year, the security forces in Cameroon have used torture without fear of repercussion," said Lewis Mudge, Central Africa director for HRW.
The report cited former detainees who say suspects had been tortured or humiliated to force them to confess or sign statements they were not allowed to read or were unable to read in French.
On Wednesday, Cameroon's defence ministry denounced on Facebook what it said was the "complicit silence" of HRW, Amnesty International and the foreign media about acts carried out by separatists.
On October 1 2017, radicals declared the creation of the "Republic of Ambazonia," covering two English-speaking regions incorporated into francophone Cameroon in 1961.
The declaration went largely unnoticed outside Cameroon, and "Ambazonia" -- named after a bay at the mouth of the Douala River -- has been recognised by no-one.
Separatists have been blamed for attacks on police stations and schools and for staging mass kidnappings.
The UN Security Council will hold its first meeting this month to discuss the country's separatist conflict.
"The UN Security Council should send a clear message that ending torture in detention is critical to addressing the crisis in Anglophone regions," HRW said.
In April, HRW said one its researchers was denied entry into the country in what the group says was an attempt by authorities to hinder reporting on abuses.