Man arrested in London train attack; threat level remains ‘critical’

LONDON – Police have arrested an 18-year-old man on England’s southeast coast in connection with the detonation of an improvised bomb on a London tube train that injured at least 29 people.

The man was arrested Saturday in the port area of Dover, a major ferry hub for travel to France, and is being held under a section of the United Kingdom Terrorism Act, the Metropolitan Police said in a statement.

“We have made a significant arrest in our investigation this morning,” Neil Basu, senior national coordinator for counterterrorism policing, said in the statement. “Although we are pleased with the progress made, this investigation continues and the threat level remains at critical.” The man in custody wasn’t identified by police.

The U.K. terrorism threat level was raised to “critical,” indicating that further attacks may be imminent, Prime Minister Theresa May said late Friday, as police hunted for suspects who set off the improvised bomb at the Parsons Green station about 8:20 a.m., causing what witnesses described as a fireball.

May said earlier that the device was “intended to cause serious harm.” Sky News broadcast images of a small fire in a bucket and Lidl shopping bag with wires protruding and said the device, which had a timer, had probably not detonated fully.

In the Saturday update, London police said the public should “remain vigilant” as it works through a “complex investigation.” 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.

In an apparent U.S. leak, CBS reported that the explosives were consistent with those used in another recent attack. The U.S. and U.K. have close intelligence-sharing ties and the U.K. has publicly criticized U.S. leaks of police intelligence after previous attacks.

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 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 Islamic State. On Friday, the Amaq news outlet said the London explosion had been carried out by a “group following the Islamic State.”

After the explosion at Parsons Green station in southeast London, passengers were caught in a stampede as they tried to flee. Ambulances rushed people to hospital, although the injuries weren’t life-threatening with most suffering what police called “flash burns” to their faces, hands and hair.