Police are appealing for witnesses after a teenager was robbed on Leagrave High Street on Sunday.
The incident took place near the junction with Copperfields at around 4.55pm on August 18.
A boy approached the victim on a bike, threatened him with a black handled knife concealed in a bag, and stole his silver iPhone 8.
The suspect is described as Asian, aged between 15 and 17 years old, around 5’6” and with no facial hair.
He was riding a grey mountain bike and wearing a black top with EA7 on it, dark coloured bottoms and a black pouch style bag over his shoulder.
Investigation Officer Gillian Cook-Smith said: “No one should face violence or the threat of violence on our streets.
“This would undoubtedly leave anyone shaken and I would urge anyone who can help our investigation to get in touch.”
Anyone with any information is asked to contact police on 101 or visit the online reporting centre on the Bedfordshire Police website, quoting reference 40/47776/19.
You can also contact Crimestoppers, anonymously, on 0800 555 111.