British Transport Police (BTP) detectives are looking for three men after a man was assaulted at Stratford London Underground station - just for bumping into them.
The incident happened at around 10.15am on Tuesday, 10 February, on the westbound Central line platform.
Detective Inspector Chris Neeson said: "A 25-year-old man was attacked by a group of three men after accidentally bumping into them. He suffered serious facial injuries in the attack.
"The Tube network is a safe place, and incidents like this are rare, but when they do occur, BTP will do everything in its power to bring the perpetrators to justice."
As part of their investigation into the incident, detectives have been examining CCTV from the station.
They have now issued three images of men who they believe have important information about what took place.
DI Neeson said: "We need to find the people who carried out this attack. I am confident the men in the images can help us. Who are they?"
Anyone with information is asked to contact British Transport Police on 0800 40 50 40, or text 61016, quoting reference TSUB/B4 of 23/03/2015. Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.