A murderer has gone on the run from prison and could be a danger to the public, police warned.
Brian Grady, also known as Brian Revill, walked out of HMP Prescoed in South Wales on Monday and failed to return, Gwent Police said. HMP Prescoed is a minimum-security prison near Usk in Monmouthshire.
The 26-year-old was jailed for at least 11 years in July 2003 at Bristol Crown Court after being convicted of murder and robbery.
But he has now disappeared, and police believe he could be in the Bristol area, where he has contacts.
A spokesman for Gwent Police said: "We have activated our operational plan with the aim of locating him and the prison is co-operating fully with us. It is believed there may be a potential risk to the public due to the fact that he is no longer in the custody of the prison service."
Grady is described as white, 5ft 11in, of average build, with short light brown hair and blue eyes. He has a scar under his left eye and speaks with a Bristol accent. He is not a registered sex offender, police said.
Members of the public are warned not to approach him but to call police if they have any information regarding his whereabouts.
Grady, from Barton Hill, Bristol, was convicted of killing Liam Attwell after the Good Samaritan tried to intervene in a mobile phone robbery.
Mr Attwell was stabbed once in the heart in the Canon's Marsh area when he confronted a group of youngsters who had set about robbing three teenage boys. The 25-year-old chef died in hospital three days later having never regained consciousness.
Sentencing Grady, Mr Justice Brian Keith said the murder had "left the city of Bristol in shock".