A teenage boy was threatened with a kitchen knife during a robbery in Wellingborough.
The incident happened at about 6pm on Monday (May 14) when a 14-year-old boy was riding the bike through the underpass and was confronted by two men.
They demanded that the boy get off the bike and threatened him with a white-handled kitchen knife until he handed the bike over.
Both men then made off towards the Hemmingwell.
A Carrera Hellcat mountain bike (pictured) was stolen during the robbery in the underpass in Eastfield Park in the town.
The offender who held the knife is described as a mixed race man, aged 20 to 30, about 5ft 10in, of medium/muscular build.
He had black hair, black stubble and wore a khaki Kings Will Dream tracksuit.
The second offender is described as a white man, of skinny build with dark brown hair and wearing khaki green cargo shorts.
Witnesses or anyone with information about the robbery can call police on 101 or Crimestoppers anonymously on 0800 555111.