Victims were spat on and assaulted in a homophobic attack on a tube from Brixton station, police say.
Detectives are appealing for victims and witnesses following the incident on Saturday, June 1.
Officers were called to the scene at around 9.55pm following reports of a man shouting homophobic abuse at passengers on board a train.
Police intercepted the service at Victoria and arrested a man. He was later further arrested on suspicion of assaulting an emergency worker and criminal damage.
A British Transport Police spokesperson said: “Officers are appealing for victims and witnesses to an assault on board a Victoria line underground service between Brixton and Victoria.
“At around 9.55pm on Saturday 1 June, officers were called to a report of a man shouting homophobic abuse at passengers on board the tube. The man then assaulted a man and spat at another. This incident is being investigated as a hate crime.
“The service was met at Victoria and a man was arrested in connection. He was also further arrested on suspicion of assaulting an emergency worker and criminal damage.
“If you witnessed the incident, or it happened to you, please contact British Transport Police. Your report will be taken seriously.”
Anyone with information is asked to contact British Transport Police by texting 61016 or calling 0800 40 50 40 with the reference 859 of 01/06/24.
Alternatively, people can contact Crimestoppers anonymously by calling 0800 555 111.