A schoolboy was assaulted by a man on the London Underground at Moor Park station.
British Transport Police are appealing for witnesses after the 14-year-old was pushed off a Metropolitan line train at around 4.15pm on Monday, December 16.
Detective constable Stephen Allen, the investigating officer, said: "A group of schoolchildren were travelling on a southbound train when a man approached a 14-year-old boy and shouted at him to get off the train.
"The man then pushed the victim with both hands causing him to stumble off the train and fall onto the platform at Moor Park London Underground station.
"We believe the man stayed on the service and left the train at Northwood station."
Investigators would like to speak with the man pictured in connection with the assault.
DC Allen said: "Violence on the London Underground network is completely unacceptable and I’d urge anyone who recognises the man pictured, or who witnessed the incident, to please contact us."
Anyone with information is asked to contact British Transport Police on 0800 40 50 40, or text 61016, quoting background LUA/B11 of 24/01/14 or contact Crimestoppers on 0800 555 111.