LONDON - One day after Parsons Green terror incident, an 18 year old man has been arrested on suspicion of a terror offence in connection with Friday's attack on a London Tube train.
The arrest was made in the port area of Dover, where passenger ferries sail to France on Saturday by Kent Police and taken to a local police station.
The arrest is "significant" but the terror threat level remains at "critical", Metropolitan Police Deputy Assistant Commissioner Neil Basu said.
Thirty people were injured after the explosion on a train at Parsons Green. Most people were treated for minor injuries and have been released, NHS England said, but three people remain in Chelsea and Westminster hospital in central London.
A further meeting of the government's Cobra emergency committee, chaired by Home Secretary Amber Rudd, ended with the recommendation that the UK terrorist threat level remains at "critical".
Mayor of London Sadiq Khan said "significant" police activity would continue over the weekend and thanked police, adding: "They are there to keep us safe".
More armed police officers will be present at London Underground stations, as well as at stations across England, Scotland and Wales, British Transport Police Assistant Chief Constable Robin Smith told the BBC.
Prime Minister Theresa May put Britain on the highest security level of “critical” late on Friday, meaning an attack may be imminent, and soldiers and armed police deployed to secure strategic sites and hunt down the perpetrators.
The home-made bomb shot flames through a packed commuter train during the Friday morning rush hour in west London but apparently failed to detonate fully.