A league table of the most violent jails in England and Wales has been revealed.
The privately-run jail at Peterborough topped the list with 115 assaults on prison officers in 2007, followed by Feltham young offenders institution in west London with 107.
A women's prison, Holloway in north London, was the third most violent with 104 attacks.
In all, there were 2,916 assaults on staff in the year, down slightly from 3,148 in the previous 12 months.
Of these, 312 were serious enough to be reported to the police, a 5% increase on the 2006 figure.
A Ministry of Justice spokesman said: "Violence in prisons is not tolerated in any form.
"Assaults on prison staff are taken very seriously and depending on the severity will be dealt with internally or referred to the police."
He added: "Any increase in the number of recorded assaults may be due to improved reporting and better data processing as well as there being more prisoners held for violent offences.
"Since 2004, a national strategy has directed every public sector prison to have in place a local violence reduction strategy."
