Two young children were kicked by a stranger at a west London Underground station.
British Transport police said the pair were with a woman when they were attacked and then fell over at White City.
The suspect immediately walked away into the transport hub and boarded an eastbound Central line train at around 4pm on December 11.
The station is outside Westfield London shopping centre near Shepherd’s Bush.
Officers released a CCTV image of a man they would like to speak to believing he could have information that may assist their enquiries.
A force spokesman said: “Neither of the children suffered any injuries but were understandably upset and the woman incredibly shaken.”
Anyone who recognises him, or who has information that could help police, should text BTP on 61016 or call 0800 40 50 40, using the reference 472 of 11 December.
