Police are hunting an escaped prisoner who could pose a risk to the public.
John Rooney, 47, left HMP Springhill in Aylesbury at 6.30am when he got a lift to Bicester.
Rooney - who is less than half-way through a 27-year sentence for kidnap and robbery - was last seen on a bus travelling towards Oxford at 7:05am.
Thames Valley Police believe Rooney may represent a risk of harm to the public.
Rooney is described as white, 5ft 8ins, slim, with brown hair.
He has tattoos on his left arm, his left wrist, hand and fingers, as well as on his right hand and letters on his right fingers, and a scar on his right hand. Tattoos on his face may not be clearly visible.
When he left the prison he was wearing a blue top, blue jeans and was carrying a bag.
Rooney, who was sentenced to 27 years in prison in 2003, is known to have links to Manchester.
Members of the public are advised not to approach him but to call 999 immediately.