Specially-trained riot officers were sent to a Hertfordshire jail yesterday after prison officers were reported to have lost control.

Prisoners in HMP The Mount, Bovingdon were said to have become violent at around 2pm yesterday in two wings of the facility.

The riot staff arrived at the jail at 6.30pm armed with shields and batons while the ambulance, fire and police crews waited outside.

The Ministry of Justice confirmed that the incident was resolved and no staff or prisoners were injured.

The wings affected hold 227 inmates, and it is said that those involved in stirring up the violence may serve longer sentences.

At 11.45pm a Prison Service spokesman said: "Specialist prison staff resolved an incident involving a number of prisoners. There were no injuries to staff or prisoners.

"The offenders responsible will be referred to the police and could spend longer behind bars."

Earlier that day the institute was criticised for struggling with staff shortages in an official report published by prison regulator the Independent Monitoring Board.

The report stated that in February that 24 of the 136 officer roles were not filled, violence grew throughout the year and that drugs were easy to get hold of.

The category C jail near Hemel Hempstead houses male prisoners and was opened in 1987.

It is said to hold more than 1,000 prisoners nearing the end of their sentences and who live close-by.