A 13-year-old was put into a headlock and punched repeatedly last Tuesday (September 20).
The victim was in Gadebridge Park with his girlfriend when an altercation occurred between him and two other boys and they assaulted him.
They also damaged the victim’s bicycle before escaping on a bicycle and scooter.
The attackers are described as two boys, aged around 15, both with a pale complexion, freckles and short ginger hair.
Inspector George Holland, from the Herts Police safer neighbourhood team, said: “I am appealing for anyone who was in the park at the time of this incident and saw what happened to get in touch.
“We’d also like to hear from anybody who saw two boys matching the description in the Gadebridge Park area, or believes they know who is responsible for this assault, to contact Herts Police via the non- emergency number 101, quoting crime reference D1/16/6759.”