Soham murderer Ian Huntley has been admitted to hospital after he was attacked by a fellow prison inmate, the Ministry of Justice said.
Huntley was attacked in Frankland Prison in Co Durham, where he is serving two life sentences for murdering schoolgirls Holly Wells and Jessica Chapman.
Reports suggested his throat had been slashed, but his condition is not believed to be life-threatening.
A spokesman for the Ministry of Justice said: “A prisoner at HMP Frankland was assaulted by another prisoner at about 3.25pm on Sunday, March 21.
“The prisoner was taken to outside hospital for treatment. His condition is not thought to be life-threatening.”
Huntley was convicted of murdering the girls, who were both 10, in December 2003 after they vanished from their homes in Soham, Cambridgeshire, in August 2002.
Yesterday's assault is not the first time Huntley has been attacked in prison.
An inmate threw boiling water on him while he was on the health care wing at the high-security Wakefield Prison in West Yorkshire in September 2005.
HMP Frankland is a Category A high security men's prison.
In 2008, HM Inspectorate of Prisons raised concerns about violence at the jail.
The Ministry of Justice would not confirm whether an investigation into the assault on Huntley had been launched.
The murder of the two girls sent shockwaves across the country during the summer of 2002.
Huntley, a caretaker at the secondary school in Soham, and his then girlfriend Maxine Carr, a teaching assistant in Holly and Jessica's junior school class, told police that they knew nothing of the circumstances surrounding the girls' disappearance.
But it emerged at their trial at the Old Bailey in December 2003 that Huntley had met Holly and Jessica as they walked past his home, enticed them inside and killed them before hiding their remains.
Huntley was given two life terms after being convicted of the girls' murders. Carr was jailed after being convicted of perverting the course of justice and has now been released from prison.