Two men have been arrested under terror laws over an attack on a prison officer at a maximum security jail.
The pair, aged 24 and 26, were arrested on Monday and are being questioned over the incident at the 458-capacity HMP Whitemoor in Cambridgeshire on January 9.
They are being held on suspicion of conspiracy to murder and preparation of a terrorist act under Section 5 of the Terrorism Act 2006, the Metropolitan Police said.
A prison officer suffered stab wounds to his head, chest and face during the attack, and four other members of staff suffered stab injuries as they stepped in to help.
The attackers were wearing fake suicide belts and used improvised bladed weapons, police said at the time.
The two suspects remain in custody at a London police station.
HMP Whitemore houses Category A and B prisoners and has a number of high-risk inmates.
Another incident in February last year saw a "small number" of prison staff there needing medical treatment after violence broke out.
