Police want to identify two young men who were caught on CCTV at around the time that two 15-year-old boys were assaulted in Chelmsford High Street.
One of the boys was punched to the back of the head by both suspects. The other boy was punched to the head after the two suspects tried to grab his mobile phone and he refused to hand it over.
Neither boy was badly hurt but they were both left upset by the attacks, Essex Police said.
The incident took place on October 31.
Both suspects are described as being in their late teens. One was black, around 6ft 2in tall, of slim build, with cropped black hair. The other was described as being of Mediterranean appearance, 5ft 9in tall, of average build with dark messy hair.
Anyone who recognises the suspects is asked to call DC Martin Amundsen at Chelmsford Police Station on 101 or ring Crimestoppers anonymously on 0800 555 111.
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