Police are appealing for witnesses after a passenger allegedly fired an imitation gun during an argument about begging on the Tube.
The incident happened on March 23 between 10.50pm and 11pm, onboard an eastbound Hammersmith & City line train at Bromley-by-Bow Underground station, police say.
Police say the incident happened after a 39-year-old passenger spoke to a man who he thought had been begging on the Tube.
The man then drew a fake handgun from his rucksack and fired, it is claimed.
The 39-year-old was left with a cut lip following the dispute.
Investigating officer Det Con Gerard Hughes said: “I am keen to speak with anyone who may have witnessed the incident or has any information relating to the incident that could help with the investigation.
A man has been charged over the incident and is due to appear on April 21 at Blackfriars Crown Court.
Anyone with any information should contact British Transport Police 0800 40 50 40 or text 61016 citing reference 301 30/03/2017.