A man with a knife has been arrested on suspicion of attempted murder by police who used a Taser at a south London train station.

Officers from British Transport Police (BTP) and the Metropolitan Police were called to Tulse Hill station just after 6.30pm on Monday after reports of a man with a knife.

Officers discharged a Taser as they detained a man on the platform at the station, BTP said.

A video on social media appears to show a man wielding a machete above his head before he is Tasered and falls to the ground.

Photos also showed several police officers surrounding a man who appears to be lying on the floor.

The man, 59, was arrested on suspicion of attempted murder and possession of an offensive weapon, the force added.

Police said there were no reported injuries and the incident was not believed to be terror-related.

Conor Fortune said he was on a Thameslink train travelling away from central London at Tulse Hill station when he heard a male voice “shouting quite loudly”.

The train conductor then told passengers not to get off because there was “a dangerous man on the platform”, he said.

The 39-year-old, from south-west London, said: “After several minutes of being sat on the platform, the driver announced that we were being held and she shut the doors as a precaution, and advised nobody to get off as there was ‘a dangerous man on the platform’.

“She informed us the police had been alerted and were responding.”

He added that he had been impressed by the train driver’s professionalism and at the rapid police response.

Ash New, who commutes into central London from Tulse Hill every day, said he arrived at the station on his way home after the man had been detained.

The 27-year-old, who lives a few minutes from the station, said he saw police officers with bags collecting evidence on the opposite platform.

He also saw a number of people who looked “a bit shaken” as they were being spoken to by police.

He said: “I think there was a lot of confusion. People were not really sure what was going on.”

He added that he was shocked to see around a dozen police cars outside the station.

Any witnesses should contact BTP by sending a text to 61016 or by calling 0800 40 50 40 quoting reference 478 of 14/01/2019.