Detectives are appealing for witnesses following a series of robberies on return trains between Broxbourne railway station and both Cambridge and Hertford.
From around 3.15pm (18 January) until past midnight today a group five teenagers were seen taking several trains along the line between Broxbourne and Cambridge, threatening and robbing passengers.
The suspects are described as being aged between 14 and 17 with Irish accents.
Officers believe many people witnessed the incidents or were victims of additional crimes not yet reported.
Anyone with who witnessed the incidents or has information is asked to contact BTP by texting 61016 or by calling 0800 40 50 40, quoting reference 6 of 19/01/2024.
Alternatively, you can contact Crimestoppers anonymously on 0800 555 111.