This improvised explosive device was placed on a London tube train earlier today. It failed to fully detonate, but caused a fire that injured twenty-nine people.

The Islamic State has claimed responsibility for the bombing on a London tube train this morning. The group’s Amaq News Agency first released a short statement claiming that a “detachment” carried out the attack. The Islamic State then released a longer statement saying that “soldiers of the caliphate” had placed “several” bombs and exploded one of them.

The jihadists did not provide any specific details about the perpetrator(s). British authorities have not yet publicly identified any suspects, nor have they confirmed that multiple bombs were placed throughout London.

British authorities say they are still hunting “those responsible” and it remains to be determined what connections, if any, there are to the self-declared caliphate.

“Hundreds of police officers are pursuing numerous lines of enquiry, trawling through hours of CCTV footage and speaking to witnesses,” Mark Rowley, the Assistant Commissioner of the Metropolitan Police, told the press.

The bombing occurred just after 8am local time at the Parsons Green Underground Station. An improvised explosive device (IED) was placed on the train, but apparently did not completely detonate.

Photos released by authorities show the remains of the IED, which was placed in a large white bucket. Wires can be seen sticking out and there are other identifiable elements as well. Had the bomb fully exploded, it is unlikely that any such details would be visible. The IED did cause a fire, which injured more than two dozen people.

The fact that much of the bomb remained intact means that authorities likely have more forensic clues. “The device and remnants left at the scene have been taken away and are being examined by forensic experts,” Rowley said. “While this work is ongoing, there is no doubt in my mind that those responsible intended to cause great harm and injury.”

The Metropolitan Police (UK) quickly deemed the incident a “terrorist” attack, saying that 18 people had been hospitalized “mainly” due to the burns they suffered. The number of wounded climbed throughout the day, however, with 29 people receiving some form of medical attention. The London Ambulance Service reported that none of the victims were “thought to be in a serious or life-threatening condition.”

The UK has been struck by jihadists several times this year.

On Mar. 22, a man drove his vehicle into pedestrians outside of the British Parliament and then assaulted others with a blade.

On May 22, a suicide bomber detonated his explosive device outside of the Manchester Arena, where an Ariana Grande concert had just concluded. Twenty-two people were killed and dozens more injured. It is possible that Islamic State operatives in Libya or elsewhere played a role in the bombing.

On June 3, three terrorists attacked London Bridge and the nearby Borough Market, first by ramming their vehicle into pedestrians and then wildly stabbing at people dining or drinking at local establishments.

UK officials report surge in terror-related arrests

While several attacks have now killed or wounded dozens of victims, UK authorities say they have stopped even more from being launched through terror-related arrests and other measures.

The UK Home Office reported this month that there were “379 arrests for terrorism-related” offenses for the year ending June 2017. This was “an increase of 68% compared with the 226 arrests in the previous year” and “the highest number of arrests in a year since the data collection began in 2001.”

Fifty-six of the 379 arrests were conducted in connection with the aforementioned attacks on Mar. 22, May 22, and June 3 — all three of which were claimed by the Islamic State.

Not all of the arrests resulted in terrorism charges being brought. Suspects were released without charge in half the cases. In 123 cases a charge was brought and 105 of these involved “terrorism-related” offenses.

As of June 30, according to the UK Home Office, “there were 204 persons in custody in Great Britain for terrorism-related [offenses], an increase of 35% on the 151 persons in custody as at the previous year.” This continues “the upward trend seen in terrorist prisoners over the last few years.”

Of the 204 people in custody, “the majority (91%) held Islamist extremist views.” A “further 5% held far right-wing ideologies, and 4% other ideologies.” In its report earlier this month, the UK Home Office published the bar chart below showing the number of people in custody due to suspected terrorism-related offenses since June 2015:

Earlier this year, British officials said they were investigating 500 possible plots involving 3,000 people on the “top list” of suspects at any given time. In addition, 20,000 other people are on the counterterrorism radar for one reason or another and are still considered potentially problematic.

The British government previously warned that the Islamic State has created an “unprecedented” level of threats, both in terms of “range” and “pace.” [See FDD’s Long War Journal report, Why the UK launched its first targeted drone strike ever.]

Thomas Joscelyn is a Senior Fellow at the Foundation for Defense of Democracies and the Senior Editor for FDD's Long War Journal.

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