Detectives are hunting a man who escaped from police custody while receiving hospital treatment.
Ryan McManus, 21, had his spleen removed last week and was still being treated in hospital when he ran away.
He was arrested on conspiracy to commit robbery on September 10, shortly before having the operation, a police spokesman said.
McManus, of Great Cheetham Street, Broughton, Greater Manchester, should not be approached, she added.
He was due to stay in hospital for daily injections to prevent infection, for pain relief and to monitor any complications. But he left Salford Royal Hospital at 12.10pm yesterday.
He is described as 5ft 7in, of slim build with a shaved head and blue eyes and has a scar on his chin and scars on his back from the surgery. He was wearing a grey vest, grey shorts and navy blue trainers.
Assistant Chief Constable Ian Hopkins said: "Ryan's welfare is our top priority, he has just been through major surgery and needs the care of medical professionals to recover.
"We are extremely worried about the risks he is posing to his own health by going on the run. If you have seen him or know where is, please do not approach him but call us immediately."
The circumstances surrounding his arrest have been referred to the Independent Police Complaints Commission, the spokesman added.
Anyone with information is asked to dial 999 in an emergency, 0161 856 9283 for non-urgent calls or to call Crimestoppers, anonymously, on 0800 555 111.