Would-be robbers reportedly attacked a teenager while trying to steal his bike.

The group of four males approached the 13-year-old boy while he walked in the alleyway behind Redcliffe Street with his bicycle between 7.50pm and 8.05pm on Wednesday, February 7.

Police say the group – one of whom is believed to have been carrying a knife - assaulted the boy “numerous times” and attempted to take his bike.

A witness then ran to the victim’s aid, which caused the suspects to flee the scene and leave the bike with its owner.

The witness has been identified by officers who are appealing for information about the incident.

CCTV images of people the police would like to speak to in connection with the attempted robbery have been released.

A Wiltshire Police spokesperson said: “Enquiries are ongoing.

“Anyone with information should call 101 and quote crime reference number 54240015135.

“Alternatively, call CrimeStoppers anonymously on 0800 555 111.”