Detectives are appealing for information to trace a missing pensioner from Stevenage.
Arthur Headington, 78, of Dovedale, was last seen at 9.30am on Friday at Collenswood Road.
He was last seen wearing a black coat and blue jeans. He is bald but may be wearing a brown and cream checked flat cap.
Det Insp Jim Luxon, investigating Arthur's disappearance, said : "We are growing increasingly concerned with every minute that passes for Arthur's welfare.
"I would urge anyone who may have seen Arthur or who may have any information at all which could assist us to call us immediately on 101."