By Ange Ngu Thomas
BBC correspondent in Douala
The US state department has issued a scathing report on the condition of prisons in Cameroon as well as the general state of human rights in the country.
The criticism, which comes at a time when the Cameroonian Government is trying to gain favour with the US, paints a picture of large-scale overcrowding, poor nutrition and lack of basic medical attention.
President Paul Biya stands accused of ethnic bias
It said 7,000 prisoners are detained at the New Bell Prison in the economic capital Douala, originally intended for only 1,500.
The Kondengui maximum security prison in the capital Yaounde which was initially meant for 2,000 inmates is now home to 9,530 detainees, most of them awaiting trial.
The conditions are the same in other major cities like Bafoussam in the west, Bamenda in the north-west and Garoua in the north of the country.
The report, picked up by the local press, also condemned the detention of juveniles alongside adults and the slow process of bringing detainees before the courts.
The security operatives were also accused of several unlawful extrajudicial killings and the disappearance of political opponents of President Paul Biya's administration.
It further cites the Cameroonian Government's failure to account for nine detainees who are alleged to have disappeared from the Bafoussam prison in March last year.
On political rights, the US report noted that in successive elections pro-opposition supporters had been disenfranchised making it difficult for citizens to effect any meaningful change to the government.
The appointments of key cabinet ministers and military officials from Mr Biya's Beti clan was also criticised in the report.
It said that 200 other ethnic groups have largely been ignored in political appointments.
The report finally condemned the clampdown on private audio-visual media houses and the harsh media laws which have stifled press freedom in Cameroon.
The government has not yet issued any official reaction to the report.