Thieves, including one carrying a gun, attempted to rob a group of teenagers.
The boys were in an alleyway connecting Honey Lane and Round Hills in Waltham Abbey at 6.50pm on Friday when they were approached by three men.
The men demanded the boys hand over their mobile phones, but ran away empty handed when one of the boys said the police were on their way.
The men were described as white, about 19-years-ol,d of medium build.
Anyone with information can call police on 101.