Four males attempted to rob a teenage boy in an alleyway assault.
A 13-year-old boy was walking in the alleyway behind Redcliffe Street in Swindon when he was approached by four males, one of whom is believed to have had a knife, between about 19:50 GMT and 20:05 GMT on 7 February.
The men assaulted him several times and tried to steal his bike.
Police have released CCTV images of people they would like to speak to.
A witness, who has since been identified by Wiltshire Police, ran to the victim's aid, causing the suspects to run off, leaving the bike at the scene.
As they continue their enquiries, the force has asked anyone with information to get in touch.