UK police arrest second suspect in train blast as probe widens

(Bloomberg) The UK arrested a second suspect in connection with a blast on a commuter train as London’s counter-terrorism police widened their investigation into the attack that injured at least 30 people. The UK threat level remained at critical, meaning another attack may be imminent.

Police arrested a 21-year-old man in Hounslow, southwest London, late on Saturday, the Metropolitan Police said in a statement. He was being held under the UK's Terrorism Act in a south London police station. Police on Saturday morning arrested an 18-year-old man in the departure area of the port at Dover, the main ferry link between the UK and France that saw over 12 million passengers in 2016.

Prior to the second arrest, officers had evacuated residents in a section of Sunbury-on-Thames in Surrey, about 24 kilometers southwest of London, as they searched a home as "a precautionary measure" after the arrest, according to a statement.

That search "will take some time," Neil Basu, the Metropolitan Police’s senior national coordinator for counter terrorism policy, said in a statement. "We are keeping an open mind around whether more than one person is responsible for the attack and we are still pursuing numerous lines of inquiry and at a great pace."

Police have identified 121 witnesses to the attack at the Parsons Green station on Friday and spoken to 100 of them already. Officers continue to trawl through hours of closed-circuit television footage and videos and photographs sent by members of the public, Basu said.

‘Significant’ Arrest

It’s too early to reach any conclusions in the case, and police are working hard to learn more details about the suspect following a series of attacks in the country, Home Secretary Amber Rudd said on the BBC’s Andrew Marr Show on Sunday.

"This has been a year like no other,’’ she said. On Saturday, she said the arrest in Dover was "significant."

Troops have been deployed as part of an operation to free up some 1,000 armed police so they can protect transport hubs and events.

The attack is the fifth this year in the U.K. and Londoners are growing accustomed to the sight of armed police patrolling the transport network. Police said on Thursday that terrorism-related arrests had risen 68 percent over the past year.

Earlier this year assailants with vans and knives attacked passers by on Westminster Bridge and London Bridge in two separate strikes, and a van was driven into worshippers outside a mosque in Finsbury Park. A suicide bomber attacked a concert venue in Manchester in May, killing more than 20 people including children and mothers. The terror threat level was raised to critical after that attack and lowered four days later to severe, meaning an attack is considered highly likely but not imminent.

Most of the attacks have been claimed or praised by the jihadist group Islamic State. On Friday, the Amaq news outlet said the London explosion had been carried out by a "group following the Islamic State."