London Tube attack: 18-year-old arrested as terror threat raised to 'critical'

London [U.K.], September 16 (ANI): Police in England have arrested an 18-year-old teen ager in the port area of Dover in connection with Friday's terrorist attack on a train at a London underground station, London's Metropolitan Police said.

It was a "significant arrest" as the investigation continues,The Guardian quoted statement of Deputy Assistant Commissioner Neil Basu, the senior national coordinator for counter-terrorism policing.

The arrest came 24 hours after a homemade bomb partially exploded at Parson Green tube station in west London, injuring 29 people.

"This arrest will lead to more activity from our officers. For strong investigative reasons, we will not give any more details on the man we arrested at this stage," he said.

ISIS have claimed responsibility for the explosion on the London underground at Parsons Green.

Metropolitan Police said that further investigations will continue and the 18-year old will be asked whether there were other conspirators involved in the attack. Detectives will also look into the CCTV footage before and after the attack to track movements of those they suspect of involvement.

Any computer and phone owned by a suspect will be examined for clues, plus the remnants of the smouldering improvised explosive device left on the tube train will also provide forensic clues.

The London's Metropolitan Police said, "Kent police had arrested the man in the port area of Dover on Saturday morning under section 41 of the Terrorism Act under which a police officer can arrest someone whom they reasonably suspect to be a terrorist."

The man was taken to a local police station and will be driven under guard to a south London police station.

Prime Minister Theresa May has announced that the security services are raising the terror threat level from "severe" to "critical" in the wake of the Parsons Green terror attack.

The Prime Minister announced the first stage of Operation Temperer would be going into effect, which means armed troops will be sent to key locations including nuclear sites, freeing up armed officers to police the streets.

Joint Terrorism Analysis Centre has raised Britain's terrorism threat level from "severe" to "critical," meaning an attack is expected imminently,on fears that whoever was behind the attack, and the materials used to make the device, were unaccounted for.

The UK's terrorism threat level is being reviewed "hour by hour" as developments in the investigation unfold, the Guardian reported. (ANI)