An 18-year-old man has been arrested on suspicion of terror offences in connection with Friday’s attack on a London Tube.

The man was detained in the port area of Dover on Saturday by Kent Police and is being held at a local station.

Metropolitan Police Deputy Assistant Commissioner Neil Basu said the arrest was “significant”, but the terror threat level remains at “critical”.

Thirty people were injured after the explosion on a train at Parsons Green.