Police officers attend the scene of the London Bridge attack as UK counterterrorism police search for clues. Photo / AP
London Bridge attacker Usman Khan was tackled by other former offenders, including a murderer, who had been invited to a conference on rehabilitation, after he started "lashing out", it has emerged.
Khan had previously participated in Cambridge University's Learning Together prisoner rehabilitation programme but had showed "no cause for concern", a source with knowledge of the programme said to AAP.
A number of former participants, including Khan, had been invited to take part in a conference to mark the programme's fifth anniversary at Fishmongers' Hall on Friday.
Khan reportedly started "lashing out" in a room downstairs and was heading upstairs when he was tackled by the other conference-goers and "bundled out" of the front door past a room of unarmed people.
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.
At the time of the incident they were all either on day release, or had been released on licence.
One of the group was James Ford, who had committed the murder of a woman with the mental age of a 15-year-old, in 2014.
Amanda Champion, 21, was strangled and slashed across the throat by Ford in a completely random attack in Ashford, Kent.
Ford was caught after a Samaritans worker broke a vow of anonymity to tell police that a man who had phoned the confidential service 45 times had confessed to killing a woman.
Khan, the terrorist who killed two people at London Bridge and injured several others, had a string of previous terror offences.
The 28-year-old, who was shot dead by police, had previously been jailed for his role in the Stock Exchange terror plot which was disrupted by British security officials.
Khan was just a teenager when he was first recognised by security services, after he joined a group of men who preached a radical interpretation of Islam.
This attack took place under a year after he was released from prison.
One of the victims was named in British media reports as Jack Merritt, a graduate of Cambridge University who was helping organise the conference where the attack began.
Grieving dad David Merritt today paid tribute to his son as a "beautiful spirit".
Writing on Twitter, he said: "My son, Jack, who was killed in this attack, would not wish his death to be used as the pretext for more draconian sentences or for detaining people unnecessarily.
"RIP Jack: you were a beautiful spirit who always took the side of the underdog."
He said his son had been a "champion" for those who had "dealt a losing hand by life, who ended up in the prison system".
David added the Cambridge community was in "shock" after the attack.
He has since deleted the Tweets.
In the wake of the tragic news, friends also shared tributes to Jack.
One wrote: "David, I knew your son through Learning Together & I loved him to pieces - he was the sweetest, most caring and selfless individual I've ever met.
"The warmest heart, always with time for anyone. Completely irreplaceable - I will mourn his loss greatly and honour his memory xxxx."
Neil Basu, the Metropolitan Police counterterrorism police, said he could not name the victims until they had been formally identified by the coroner.
Khan was a teenager when he was first recognised by security services.
At age 19, he was the youngest in a group of four men from Stoke-on-Trent who participated in a local branch of Al-Muhajiroun — a militant jihadist organisation that included notorious radical cleric Anjem Choudary.
According to Sky News, Khan was a "student and personal friend" of Choudary's, a controversial figure who has been denounced by mainstream Muslim groups and widely criticised in UK media for his extremist views.
The group of nine attracted the interest of British security services, including MI5, after they went public attempting to convert others to their radical interpretation of Islam.
During this time, they plotted to bomb a number of local pubs, and planned to open a militant training camp in land owned by Khan's family in Kashmir, according to The Independent.
Khan and accomplice Nazam Hussein planned to use an Islamic religious school as a base to offer firearms training for jihadist operations in Kashmir and Pakistan.
The pair eventually formed a group of nine from across the UK to achieve their goals. They came up with numerous targets for a terror attack including Westminster Abbey, the London Eye, Boris Johnson's then-Mayoral Office, the US Embassy and the Church of Scientology.
Finally, they settled on placing a pipe bomb in a bathroom at the London Stock Exchange. But before he could travel to Kashmir in January 2011, Khan was arrested along with several other members of the group under Operation Norbury.
He was jailed in 2012, and initially handed a minimum sentence of eight years, as well as being monitored for 30 years following his release.
This indefinite sentence was later relaxed after an appeal, with Khan told to serve eight years of a 16-year fixed term sentence.
Lord Justice Leveson said at the time: "There is no doubt that anyone convicted of this type of offence could legitimately be considered dangerous.
"There is an argument for concluding that anyone convicted of such an offence should be incentivised to demonstrate that he can safely be released; such a decision is then better left to the Parole Board for consideration proximate in time to the date when release becomes possible."
Khan was allowed to walk free in December 2018. Less than a year later, he would carry out his attack on the London Bridge.
In a bizarre development, it has emerged that Khan may have attended a story telling and creative workshop at Fishmongers' Hall just moments before he threatened to blow up the venue.
Ironically the University of Cambridge-organised conference was on prisoner rehabilitation.
University Vice-Chancellor Professor Stephen Toope said he was "devastated" that an event organised by its Institute of Criminology was targeted in the attack.
"I am devastated to learn that today's hateful attack on London Bridge may have been targeted at staff, students and alumni attending an event organised by the University of Cambridge's Institute of Criminology," he said.
"We are in touch with the Metropolitan Police, and awaiting further details of the victims.
"We mourn the dead and we hope for a speedy recovery for the injured. Our thoughts are with all their families and friends."
THE TIMES: The terrorist wearing a tag #TomorrowsPapersToday pic.twitter.com/oSH6wKckRp
— Neil Henderson (@hendopolis) November 29, 2019
Khan was a guest at a Cambridge University conference on prisoner rehabilitation when he threatened to blow up the historic Fishmongers' Hall.
He was wearing a fake suicide vest and had two knives in his possession when he carried out the attack.
The programme for the Learning Together event, organised by the University's Institute of Criminology shows attendees enjoyed a "brunch and chat" between 11am and midday local time.
The convicted terrorist launched his attack halfway through an interactive workshop featuring storytelling and creative writing that ran from 12.15pm to 2.15pm local time.
After threatening to blow up Fishmongers' Hall, the double knife wielding Usman was reportedly chased by bystanders, including some fellow attendees onto London Bridge where he went on a stabbing rampage.
A man who grabbed an iconic narwhal tusk mounted on the wall of the hall and another armed with a fire extinguisher took Usman down with the help of tour guides Thomas Gray and Stevie Hurst.
NHS chief executive Simon Stevens confirmed two victims had died, with three more seriously injured, one of them critically.
"Our heartfelt thanks go to everyone who responded to this incident, both the extraordinarily brave members of the public and our emergency responders," Stevens said.
"As the Met police have confirmed, sadly two people have died in addition to the suspect. London Ambulance Service treated people at the scene and three were taken to hospital.
"We can confirm that one patient is critical but stable, a second person is in a stable condition and a third person has less serious injuries.
"Our deep sympathies are with the families and all those affected by today's incident."
Australian Prime Minister Scott Morrison said on Twitter: "Just terrible news out of London and The Hague", referring to a second stabbing attack in The Netherlands.
"Whether it has been the despicable acts of terrorists in the UK, or as yet not determined in the Netherlands, Australians' deepest sympathies are with the victims and their families — they were innocent people going about their lives."
Just terrible news out of London & The Hague. Whether it has been the despicable acts of terrorists in the UK, or as yet not determined in the Netherlands, Australians’ deepest sympathies are with the victims & their families - they were innocent people going about their lives.
— Scott Morrison (@ScottMorrisonMP) November 29, 2019
UK Prime Minister Boris Johnson paid tribute to the "extraordinary bravery of members of the public who physically intervened".
"To me they represent the very best of our country and I thank them on behalf of our country," he said, adding that the perpetrators would be "hunted down and be brought to justice."
"One cannot help but think back to what happened in 2017 in the same part of the city," he said in reference to the attack that killed eight people and injured 48 after three men drove a van into pedestrians and terrorised patrons in Borough Market with knives.
Witnesses reported hearing gun shots during the middle of a busy Friday afternoon.
Amanda Hunter said she was on a bus when it came to a stop.
"There was a commotion and I looked over the window and I saw three police officers running over to a man who had something in his hand, I don't know what," she said.
"I saw a police officer shoot him."
"I saw a man and three police officers trying to put him on the ground and then I heard about three shots go into the man and then police officers went away from the suspect."
Someone just shot on London Bridge #london @BBCBreaking @SkyNews pic.twitter.com/qVk5IPmofb
— amanda** (@AmandaHunter87) November 29, 2019
One woman who didn't want to be named said: "I was just walking along the bridge and I heard four or five shots from behind me.
"I just ran. I didn't even look back. I've no idea of it was police or not. I was terrified."
Bus driver Mustafa Salih, 62, was travelling from Borough High St towards London Bridge where he saw emergency vehicles and the police cordon.
He told BBC London: "A police officer came up to me and said turn off your engine, get off and run.
"I looked up and I could see a crowd of people coming towards me.
"One woman was crying. I ran back down to Borough High St. It was all very scary as we did not know what was happening."
BBC reporter John McManus was in the area and said he saw figures grappling on the bridge. He said: "I thought it was initially a fight," but then shots rang out.
Guardian journalist Owen Jones said he had just cycled to the area and found police yelling "keep moving" while ushering people behind the cordon.
"It was a very tense atmosphere," he said. "You're in the middle of an urban area with police yelling keep moving … you know that something is very clearly off."
"The whole area is crawling with police. The scene is one of extreme confusion."
The factory had produced 6616 tons of toxic gases by the war's end.