Two prisoners have escaped from Pentonville prison in north London.
The Ministry of Justice announced the escape from the Islington prison this afternoon. The prisoners have not yet been named.
A Prison Service spokesperson said: "Two prisoners at HMP Pentonville were found to be missing on Monday 7 November.
"Public protection is our top priority and we take escapes from custody extremely seriously. We are working closely with the police and are urgently investigating the matter."
It has been reported that the inmates saw through the bars of their cells before escaping over the wall of the prison, and fooled guards using mannequins, but this has not been confirmed by the Ministry of Justice.
HMP Pentonville, which opened in 1842, is situated just off Caledonian Road, and houses around 1,300 inmates.
The escape comes weeks after inmate Jamal Mahmoud was stabbed to death at Pentonville in October. Around half of the prison's 200 officers passed a vote of no confidence in its governor, Kevin Reilly, after the murder.
Meanwhile, just last night extra officers were brought in to HMP Bedford in order to control a riot that broke out among prisoners.