Liverpool captain Virgil van Dijk is “praying for a speedy recovery” for those hurt after a car ploughed into a crowd following the Reds’ Premier League trophy parade in the city on Monday evening.

A 53-year-old man was arrested after a car struck several pedestrians on Water Street, close to where the parade had finished, with 50 people injured – including one child who was seriously hurt.

In a post on Instagram Stories, Van Dijk wrote: “My thoughts and prayers are with everyone affected. Praying for a speedy recovery for everyone who suffered injuries. We are all with you.”

Van Dijk’s post came after his former boss Jurgen Klopp, who attended Sunday’s final game of the season against Crystal Palace before watching Monday’s parade from a position on the Strand, close to where the incident would later occur on Water Street, offered support to those affected in his own post.

“My family and I are shocked and devastated,” Klopp wrote on Instagram. “Our thoughts and prayers are with all those who are injured and affected. You’ll never walk alone.”

Liverpool chief executive Billy Hogan said in a video posted on the club’s website: “This weekend was one of celebration, emotion and joy spread across the city in our entire fan base, and it ended in unimaginable scenes of distress with this appalling incident.

“I’d like to pay tribute to our emergency services and partner agencies – Merseyside Police, North West and St John Ambulance Services, and Merseyside Fire and Rescue – who dealt with the incident, and now our hospital staff across the city who are dealing with those who are injured, including tragically four children.

“I would also like to thank our supporters who witnessed this event and helped each other where they could.

“We continue to work with the emergency services and the local authorities to support their ongoing investigation and once again we would ask if anyone has any further information about the incident, please contact Merseyside Police.”

Liverpool’s local rivals Everton issued their own statement saying they were “deeply saddened by the horrific incident” and calling on anybody with information regarding it to contact Merseyside Police.

“Our thoughts are with all those affected at this incredibly difficult time and we extend our best wishes for a full recovery to those who were injured,” the statement read.

Merseyside Police said the suspect was the driver of the car, white, British and from the Liverpool area, and added that it was not being treated as terrorism.

Liverpool’s metro mayor Steve Rotheram said four people are still “very, very ill in hospital”, and said the “big question” is what the car was doing on a closed road.

Speaking to reporters at the scene on Tuesday, Rotheram said: “Water Street was not a route where vehicles were supposed to be using it, it was blocked off.

“At this end of it, which is the direction that it was coming in, towards The Strand, there were literally hundreds of thousands of people here, so no vehicle would have got through anyway.

“The questions, I suppose, are legitimate, but we have to give the police the time to conclude their investigations, which is what they’re doing.”

Footage of the incident circulating online appeared to show people in the crowd following Liverpool’s celebrations attempting to get close to the driver of the car, with one managing to open the driver’s car door.

Videos then appeared to show the driver close the car door before suddenly speeding up and veering into pedestrians on both sides of the crowded street.

The clips posted on social media then showed people from the crowds attempt to chase the driver – with some kicking the vehicle and smashing the back window.

Officers quickly surrounded the car as witnesses attempted to stop the driver, who was eventually detained by police.

The Prime Minister said he was in close contact with Rotheram about the incident, adding: “Scenes of joy turned to utter horror and devastation, and my thoughts and the thoughts of the whole country are with all of those that are affected, those injured, which of course includes children, their families, their friends, the whole community, Liverpool fans everywhere.”

Sir Keir Starmer also said it was a “matter for the police” that they gave details about the man who was arrested.

Nick Searle, Merseyside Fire and Rescue Service chief fire officer, said four people who were trapped under the car, including a child, were rescued by firefighters.

At a press conference late on Monday evening, Dave Kitchin from North West Ambulance Service (NWAS) said 27 people were taken to hospital and 20 people were treated at the scene, with four children among the injured.

He said two of those taken to hospital, including one of the children, suffered serious injuries.