A knife man launched an attack on a fellow passenger on the London Underground in the early hours of Sunday morning.
A spokeswoman for the British Transport Police (BTP) confirmed they were called to reports a man had been assaulted on a Tube at South Wimbledon underground station at around 4.10am on Sunday, March 19.
The victim was slashed in the face and treated by paramedics at the station.
A 51-year-old man from Colindale, Barnet, was arrested on suspicion of possession of a knife blade / sharp pointed article in a public place.
He has been bailed until Monday, April 17, while enquiries are ongoing.
The Northern Line was closed between Stockwell and Morden until 5.10am.
No service between Morden to Stockwell, while the police carry out an investigation at South Wimbledon.— Northern line (@northernline) March 19, 2017