Isis has claimed the London Bridge terror attack was carried out by one of its fighters.
The terrorist organisation said Usman Khan, 28, who killed two and injured several more when he went on a knife rampage in central London yesterday, acted on their behalf, reports The Daily Mail.
The group, however, did not provide any evidence this is the case as it made the claim through its news agency.
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It added that the attack was made in response to Islamic State calls to target countries that have been part of a coalition fighting the jihadist group.
"The person who carried out the London attack ... was a fighter from the Islamic State, and did so in response to calls to target citizens of coalition countries," IS said, referring to a multi-country alliance against the group.
It had previously been speculated that the attack may have been revenge for the death of Isis leader Abu Bakr al-Baghdadi.
Khan was shot and killed by armed police after he stabbed two people to death and wounded three others while wearing a fake suicide vest on London Bridge.
The attacker, who was jailed in 2012 for his role in an al Qaeda-inspired terror group that plotted to bomb the London Stock Exchange, had first been tackled and disarmed by a group of brave bystanders on the bridge.
Jack Merritt, 25, from Cottenham, was named by his father as one of two victims killed by Khan at a prisoner rehabilitation conference at Fishmongers' Hall, where the attack began yesterday afternoon.
Merritt was the course co-ordinator for Learning Together, an education scheme run by the University of Cambridge's Institute of Criminology that killer Khan had attended on Friday.
The group had been hosting a conference at the Grade II-listed building when the attack began, with Khan one of the former criminals attending the rehabilitation seminar for prisoners.
Giving a statement outside Scotland Yard, Metropolitan Police Assistant Commissioner Neil Basu said Khan was subject to an "extensive list of licence conditions" on his release from prison and that "to the best of my knowledge he was complying with those conditions".
Police were called to the north side of London Bridge at 1.58pm on Friday, after reports of a stabbing near Bank station and Fishmongers' Hall, which was hosting an event called "Learning Together".
Khan had threatened to blow up the building at the start of the rampage before he headed towards London Bridge wearing a fake suicide vest.
Minutes later, witnesses saw the knifeman being wrestled to the ground by members of the public before armed-response officers confronted him at 2.03pm and shot him dead.
Two brave members of the public chased after the knifeman, one armed with a narwhal tusk and another with a fire extinguisher.
Armed police, who confronted the suspect at 2.03pm, were heard shouting "stop moving" twice before shooting the man at close range.
Khan had previously participated in Cambridge University's Learning Together prisoner rehabilitation sessions but had showed "no cause for concern," a source with knowledge of the programme said.
The 28-year-old attacker is understood to have been invited to share his experience of prison, according to The Times.
A witness named Coralie said around 100 guests and 50 staff were in attendance.
According to the source, all those involved in tackling Khan, with the exception of the man reported to be a Polish chef, were ex-offenders.
The source said that risk assessment is "front and centre" in the Learning Together programme, due to the involvement of students.
They added that normal procedures by police and probation service had been undertaken with Khan and he had shown 'no cause for concern' up until the moment of the incident.
Khan was jailed in 2012 for terrorism offences for his part in an al Qaeda-inspired terror group that plotted to bomb the London Stock Exchange and the US Embassy and kill Boris Johnson.
In an old letter from 2012 the terrorist begged to be shown mercy as he asked for a course to be arranged so that Khan could "properly learn Islam and its teachings, and I can prove I don't carry the extreme views which I might have carried before."
He writes: "I am much more mature and want to live my life as a good Muslim and also a good citizen of Britain.
"So if you could arrange something for me and send me the details, this would be truly appreciated."
The letter emerged as a furious political row began today after it was revealed that Khan was released automatically from prison last year.
As part of the plotting, Khan's group planned to set up a training camp in Kashmir, where his family had land.
Khan, born and raised in Stoke-on-Trent, originally received an indeterminate sentence for public protection with a minimum of eight years behind bars after his 2012 arrest, meaning he would remain locked up for as long as necessary, to protect the public.
Passing judgment at the time, Mr Justice Wilkie said: "In my judgment, these offenders would remain, even after a lengthy term of imprisonment, of such a significant risk that the public could not be adequately protected by their being managed on licence in the community, subject to conditions, by reference to a preordained release date."
But this sentence was quashed at the Court of Appeal in April 2013 and he was given a determinate 16-year jail term instead, meaning he would be automatically released after eight years.
Judges including Lord Justice Leveson said at the time when reversing the original sentence that the Parole Board was best placed to decide when he would be safe to be released from jail.
But today the Parole Board has released a statement saying that Khan was released automatically and they did not make the decision.
It has also emerged today that he was a student and "personal friend" of hate preacher Anjem Choudary. Khan spent years preaching on stalls that were linked to al-Muhajiroun, the banned terror group once led by Choudary.
Yesterday's attack coincided with a similar rampage in Holland which saw three children stabbed on a shopping street in The Hague early yesterday evening, Dutch police said.
And in Paris, the Gare Du Nord train station was briefly evacuated after an alleged explosive device was found in an unattended bag.
Unverified pictures show the device, which resembles a mortar shell, inside an old duffel bag in France. However, Metropolitan Police Commissioner Cressida Dick insisted Khan acted alone.
Khan was released on licence in December 2018 and was still wearing a monitoring tag at the time of yesterday's attack, which he carried out while wearing a fake suicide vest.
British Prime Minister Boris Johnson has said that it was a "mistake" to release Khan from prison and has vowed to crack down on early releases for inmates. The PM visited the scene of the attack today with Metropolitan Police Commissioner Cressida Dick, and Home Secretary Priti Patel.
Speaking before chairing a meeting of the Government's emergency committee Cobra on Friday night, Johnson said he had "long argued"that it is a "mistake to allow serious and violent criminals to come out of prison early and it is very important that we get out of that habit and that we enforce the appropriate sentences for dangerous criminals, especially for terrorists, that I think the public will want to see".
Chris Phillips, a former head of the UK National Counter Terrorism Security Office, said today: "The criminal justice system needs to look at itself.
"We're letting people out of prison, we're convicting people for very, very serious offences and then they are releasing them back into society when they are still radicalised.
"So how on Earth can we ever ask our police services and our security services to keep us safe?
"I've said it a few times today, we're playing Russian roulette with people's lives, letting convicted, known, radicalised Jihadi criminals walk about our streets."