A teenager required hospital treatment after being attacked by a group of youths in Fairford Leys last week.
The incident happened between 6:45pm and 6:55pm on Monday September 3 while a 14-year-old boy was cycling on Brimmers Way.
He stopped for a moment and was approached by a group of ten youths.
One of the boys demanded he gave them his bike and punched him several times before another boy began kicking him.
Residents and passers-by intervened and the group ran from off the scene.
The teenager who was attacked was taken to hospital and was treated for cuts and bruises.
Investigating officer Detective Constable Carolyn Bailey said: "I would like to talk to anyone that witnessed this crime, or came out to assist this boy.
"If you did see anything, or know who these youths are, please call me on the 24 hour number 101, quoting reference number 43180269644."