A 16-year-old boy has been arrested in Balham following the fatal stabbing of a teenager.

Louis Johnson, also 16, was stabbed to death at East Croydon station in a violent attack that lasted 40 seconds on Monday afternoon.

The arrested boy was detained in Balham in connection with the murder of Louis, but details of the arrested boy's alleged involvement in the incident have not yet been disclosed.

British Transport Police said Louis came into East Croydon station at around 4.30pm through the Ruskin Square ticket barrier, and was attacked minutes later.

While he was on the overbridge in the station he met someone who immediately pulled out a knife and stabbed him, the BTP said.

Emergency services were called at around 4.45pm, but despite the efforts of medics, including an air ambulance team, he died.