London - Security forces have regained control of a prison in Britain some 20 hours after a riot by inmates, officials and media reports said Sunday. Justice Ministry officials said three prisoners sustained minor injuries.

Three-quarters of the low-security Ashwell Prison in central Britain was heavily damaged in the riot, according to the Prison Officers' Association (POA). Around 420 inmates were moved to other prisons.

POA officials said the riot was sparked by a decision to remove privileges from some prisoners. The Justice Ministry rejected speculation that the incident was over the issue of overcrowding.

Overcrowding has long been a problem in the British prison system. (dpa)