An inmate at Christchurch Men's Prison has been stabbed in the head by a group of men.

The 26-year-old was serving lunch around 12 yesterday when he was grabbed by three or four men and attacked.

Detective Sergeant Geoff Rudduck said the prisoner was stabbed in the head multiple times with a piece of wire.

"He suffered some wounds to his head which weren't life threatening. He received a number of stitches at the prison and then was returned to his wing."

Detective Sergeant Geoff Rudduck said police are investigating the possibility of a gang connection.