Theresa May last night raised the terror threat level to critical as police scrambled to identify the attackers who tried to blow up a packed Tube train during the morning rush hour, in the fourth assault to strike London this year. At least 29 people were injured in the blast and stampede, including victims requiring hospital treatment for severe burns.
Police said the device was being examined by forensics officers as investigators scoured CCTV and footage recorded by witnesses to identify the culprit.
Detectives have used CCTV images from the station and train to single out the suspect believed to have planted the homemade device, but were still working to identify the bomber.
Raising the terror status to its highest level, which means another attack is considered imminent, the Prime Minister said military personnel would replace armed police “on guard duties at certain protected sites which are not accessible to the public”.
She said: “The public will see more armed police on the transport network and on our streets, providing extra protection. This is a proportionate and sensible step which will provide extra reassurance and protection while the investigation progresses.”
Investigators fear the bomb, which left 29 passengers requiring hospital treatment after partially exploding at Parsons Green station, had the potential to cause huge devastation if fully detonated.
Isis last night claimed responsibility for the attack, in a common tactic in the wake of Western terror attacks.
In a statement a few hours later, Assistant Commissioner Mark Rowley, the UK’s most senior anti-terror police officer, suggested there may have been more than one person involved, referring to one of those behind the attack as “him” and saying police were “chasing down suspects”.
He said the force was only aware of one device, and the remnants of that device are being examined by experts.
Security sources say they were unaware of any specific plot or individuals involved in the incident.
Commuters described a “fireball” sweeping through their District Line carriage, burning off some victims’ hair and leaving some with severe burns.
The blast sparked a stampede of passengers attempting to flee the station, threatening to crush a pregnant woman and children caught in the panic.
Images of the explosive device showed flames spurting out of a white bucket inside a Lidl bag, which appeared to contain wires and fairy lights and left a “chemical smell”.
Amid initial fears that a bombmaker could have manufactured other devices than the one deployed by Salman Abedi, security services raised the UK terror threat to critical.
Unconfirmed reports suggested the Parsons Green bomb was also made from TATP and had been packed with nails.