Loi Nguyen, aged 16, was last seen leaving his home address in Bingley, near Bradford, at 1pm on Monday, May 31.
There have not been any confirmed sightings of him since and officers are said to be ‘very concerned for his welfare’ and making ‘urgent enquiries to trace him’.
Detective Inspector Michael Ineson, of Bradford CID, said: “It is now a week since Loi was last seen and we are very concerned for him. I would urge anyone who sees him or has information about his whereabouts to get in touch straight away.”
Chesterfield Road Sheffield: Man who spent 12 hours on roof is sentenced in court for affray and harassment
The Long Blondes: Leadmill cancel gig after allegations surface against band creator Dorian Cox
EuroMillions: Mystery winner from South Yorkshire has won £79,242.50 on The National Lottery
Chapeltown Sheffield rape investigation: 16-year-old arrested over assault of girl, 13, is bailed
Eurovision Sheffield 2023: Utilita Arena would have to cancel these events to make way for contest
Loi is 5ft 1ins tall, slim, has short, black hair and brown eyes.
He was wearing black shoes, a blue shirt, grey trousers and a light blue jacket when he was last seen.
Call West Yorkshire Police 101 and quote log number 1,174 of May 31.