ATTACKS in prisons are occurring once every 20 minutes, shocking figures published today reveal, as violence behind bars reaches record levels.

There were 31,025 assaults in prisons in England and Wales in the year to March — a 16 per cent increase on the previous year and almost double the figure of a decade ago.

Incidents of self-harm among prisoners also increased by 16 per cent to a new record high of 46,859 — representing an incident of self-harm every 11 minutes.