LONDON (AP) -- London Bridge reopened to cars and pedestrians Monday, three days after a man previously convicted of terrorism offenses stabbed two people to death and injured three others before being shot dead by police.
Senior politicians — who have traded blame for the security failure that allowed the attack — were due to attend a vigil at Guildhall Yard in the heart of London for the victims and to honor bystanders who fought the attacker with fists, fire extinguishers and even a narwhal tusk.
Former University of Cambridge students Saskia Jones, 23, and Jack Merritt, 25, were fatally stabbed by 28-year-old convicted terrorist Usman Khan during an event designed to connect graduate students with prisoners. Both victims worked for the Cambridge-based prisoner rehabilitation program Learning Together.
Two of the three injured people remained in hospital Monday. The third was discharged.
Khan was attending the event at Fishmongers' Hall, beside the bridge, and had returned for the afternoon session when he started stabbing people. Police believe he acted alone.
He was pursued onto London Bridge and restrained by staff from the venue and others attending the conference. Police opened fire after he flashed what looked like a suicide vest. It was a fake device.
Toby Williamson, chief executive of Fishmongers' Hall, paid tribute to staff at the venue who tried to help the injured and fight off the attacker. Williamson said one staffer, whom he identified as Lukasz, pulled a 5-foot (1.5 meter) narwhal tusk from the wall and charged at Khan, allowing others to escape. Williamson told the BBC that Lukasz suffered cuts in a minute of "one-on-one straight combat" with the knifeman.
The attack has pushed security to the top of the agenda in campaigning for the U.K.'s Dec. 12 election.
Conservative Prime Minister Boris Johnson has blamed legal changes made by a previous Labour government for the fact that Khan was freed from prison a year ago after serving half of a 16-year sentence for terrorist offenses, without parole officers assessing whether he still posed a risk.
That rule was changed in 2012 by a Conservative-led government, and Johnson has vowed to end the early release of violent offenders altogether.
Opposition parties blamed years of cuts to the prison and probation services by the Conservatives, who have been in power since 2010. Khan was on probation, subject to restrictions on his movement and wearing an electronic tag when he launched his attack.
"There are enormous questions to be learned from this terrible event that happened last week and that is, what happened in the prison with this particular individual, what assessment was made of his psychological condition before he was released and also what supervision and monitoring he was under after coming out?" said opposition Labour Party leader Jeremy Corbyn.
The family of Merritt also cautioned against knee-jerk responses. They said he "would not want this terrible, isolated incident to be used as a pretext by the government for introducing even more draconian sentences on prisoners, or for detaining people in prison for longer than necessary."
In the wake of the attack, authorities are urgently reviewing the release of more than 70 other former terrorist prisoners.
As part of that work, a 34-year-old man was arrested Saturday in Stoke-on-Trent, central England, on suspicion of preparation of terrorist acts. Police said Monday he had been returned to prison for breaching his release conditions.