Police believe the car which ploughed into a crowd at Liverpool Football Club’s victory parade, injuring 65, was following an ambulance.
The driver has been arrested on suspicion of attempted murder, dangerous driving and drug driving.
Merseyside Police Assistant Chief Constable Jenny Sims said on Tuesday the force believes the car was able to follow an ambulance crew attending to someone suffering a heart attack after a road block was temporarily lifted.
Detective Chief Superintendent Karen Jaundrill said there were a total of 65 confirmed casualties following the incident on Water Street in the city centre on Monday.
More than 50 people were treated in different hospitals and 11 people remained there on Tuesday in a stable condition.
Ms Sims defended the policing operation during the parade, saying that the force planned for “all contingencies” – including road closures and an armed police presence.
It followed the city’s metro mayor Steve Rotheram’s comments that the vehicle should not have been on the street and that questions about how the car was able to enter the road were “legitimate”.
Mr Rotheram said the mood in the city had moved from shock to reflection and relief nobody had been killed.
Providing an update on the investigation, Ms Jaundrill said the suspect, from the West Derby area of Liverpool, remains in custody and is being interviewed by officers.
The senior officer said the force received help from neighbouring forces “due to the number of victims”.
Following the events during Liverpool’s Premier League title parade, King Charles said he was “deeply shocked and saddened” to hear of the events.
“It is truly devastating to see that what should have been a joyous celebration for many could end in such distressing circumstances,” he said.
“At this heartbreaking time for the people of Liverpool, I know that the strength of community spirit for which your city is renowned will be a comfort and support to those in need.
“Our prayers and deepest sympathy are with all those who have been affected, and my special gratitude goes out to the first responders, emergency services personnel and other individuals who rushed to the aid of the injured.”
The Prince and Princess of Wales said they were “deeply saddened” by the scenes. The prince is patron of the Football Association.
Medical staff who treated those injured told the Princess Royal they were “very, very fortunate” there were not more major injuries.
Princess Anne visited the Royal Liverpool University Hospital on Tuesday where she met nurses, consultants and paramedics, as well as representatives from Merseyside Fire and Rescue Service and the football club, after 47 people were injured on Water Street on Monday.
Mr Rotheram said police now need time to conclude their investigations, but praised them for releasing details of the suspect to avoid a repeat of the riots that occurred last summer in the wake of the attack on children at a dance class in Southport. Information about the suspect was withheld at the time due to concerns over prejudicing potential trial, which allowed false rumours that the attacker was a Muslim asylum seeker to spread.
Bebe King, six, Elsie Dot Stancombe, seven, and Alice Dasilva Aguiar, nine, were killed in the July 29 attack by Axel Rudakubana, 18, who received a minimum jail sentence of 52 years.
Mr Rotheram said rumours were spread online “really quickly” after Monday’s events.
He said: “If you have a look at my timeline there was somebody very quickly saying ‘why are you lying? There’s been another incident in another part of the city’, which obviously wasn’t true.
“And then they were trying to stir up who might be responsible for it, and that’s why I think the police acted, not just appropriately, but very, very quickly, to dampen that sort of speculation because it was designed to inflame. It was designed to divide. The message of hate doesn’t go down well here.”
Asked what the police decision to release details of the suspect’s race said about the state of the country, he said: “It says that social media is a cesspit.”
Downing Street has said that police are “operationally independent” when it comes to information they choose to release.
An imam criticised social media posts blaming Muslims for the incident.
Adam Kelwick, who leads the Abdullah Quilliam Mosque in Liverpool, was at the parade with friends and family when a car drove into the crowd.
Mr Kelwick, who defused tension in Liverpool during the Southport riots last year, warned that online fake news was spreading about the perpetrator’s identity.
Mr Kelwick urged his followers to call out the fake news online, by messaging people spreading it to correct their mistake.
