This is the moment brave Liverpool football fans desperately tried to stop a driver as he rammed into fans during their Premier League trophy parade. 

Nearly 50 people have been injured after the vehicle ploughed into a group of nearly a million supporters who had gathered in the city centre yesterday - with four still seriously ill in hospital. 

As the chaos unfolded on Water Street, fearless fans attempted to rush the Ford Focus and smash its windows to get at the driver when he stalled, while others kicked and punched it from behind. 

Witnesses said car stalled for 'about 10 seconds' before it started up again and began ramming into more screaming spectators as they tried to flee. 

Today, onlookers praised the bravery of the supporters who had tried to intervene to stop the carnage.  

Peter O'Brien, who was visiting from Co Meath in Ireland, said: 'The Liverpool people really stood up to this - they were amazing and should be proud of themselves.'

A total of 27 people have been taken to hospital following the horrific incident, including four children. One child was trapped under the car with three adults when firefighters arrived to save them.

Police confirmed they had arrested a 53-year-old white British man from the Liverpool area, adding that they did not suspect a terrorist motive.  

Footage appears to show the grey Ford Galaxy struggling to make its way along Dale Street, the main business thoroughfare in the city, while hundreds of fans were still on the street.

Some could be seen banging on the car's rear and back window, before the vehicle quickly reversed and went forward, seemingly antagonising supporters.

The parade bus had passed along The Strand, the main road along the famous waterfront which was closed to traffic, just moments earlier. But Water Street, which runs off it, was packed with people walking into the city to catch trains, buses and taxis home.

Later footage seemingly showed that, by the time the car reached the end of Dale Street and entered Water Street, its back window had been smashed. The driver then went on the rampage and ploughed into the crowds.

Assistant Chief Constable Jenny Sims last night told a press conference that there were 'robust' traffic management measures in place for the parade.

However, neither Dale Street or Water were advertised as being part of 'fixed' closures before the event although 'rolling' road closures were anticipated along the route.

It is understood that Water Street was closed to traffic as part of a rolling road block as the parade reached the city centre.

A source told the Mail that there were bollards at the top of the road, at the junction of Dale Street close to the Town Hall, but these were moved to allow an ambulance to get through and the driver 'tailgated' the emergency vehicle to access Water Street.

Mr Rotheram said the 'big question' was how the horror unfolded. 'Water Street was not a route where vehicles were supposed to be using it, it was blocked off,' he said.

'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.

'And 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.'

Security expert Lee Doddridge told Sky News this morning that police had used 'totally the wrong tactic'.

He said: 'The immediate thought for me was how was a vehicle allowed to be among so many people?

'I've got to say it is just alarming that a vehicle was allowed to be so close. You allow for emergency service vehicles, it really doesn't matter at this point what the motive was, we know it wasn't terrorism, but really, a vehicle should not have been allowed anywhere near those celebrations.'

Mr Doddridge added: 'One of the images shown last night were police snipers on rooftops as if they were covering the crowd. Totally the wrong tactic. If they had focused more on preventing vehicles getting in they could have prevented this incident.

'I say could have prevent it because that's exactly what you do when you do it correctly. I do think it places a massive liability on Merseyside Police for not getting this right.'

The former counter-terrorism security adviser said police will be 'very aware of these types of incidents' and the 'tactics' used.

He explained that since 2004, police have had the power to implement an 'anti-terrorism traffic regulation order' (ATRO) 'so they can make plans and actually legally close roads so no members of the public can drive through there'.

Mr Doddridge said they can also use the National Barrier Asset, which was used extensively during the Olympics.

'The Counter Terrorism Security Adviser (CTSA) can make an application on behalf of Merseyside Police and rent the National Barrier Asset which would be deployed around those strategic areas within Liverpool to prevent vehicles coming in,' he said.

Mr Doddridge said there should have been better 'contingency planning' in place - noting this isn't the first time a trophy parade has been held after a Premier League title win.

'They could have been planning for this, watching throughout the season, have plans in place. Once they realise it's there's, they can bring that ATRO in and make sure that entire area for that parade is completely safe with only access to emergency service vehicles. 

Video circulating online showed the people carrier moving slowly along the crowded street. Pedestrians appeared to stop it and try and pull the driver from the passenger seat, shouting 'what are you doing?'

It reversed before suddenly accelerated into the tightly packed crowd of supporters, with witnesses describing the screams of victims and the sickening thud of bodies being flung over the bonnet.

The vehicle accelerated veering right then left, travelling across the street mounting the pavement, hitting men, women and even a baby, witnesses said.

When the car eventually slowed to a stop, angry fans surged forward hitting it, throwing bottles, screaming 'kill him' as others attempted to lift the vehicle to rescue pedestrians trapped under the wheels.

Within seconds, the driver was dragged from his seat before police intervened.

The shocking incident took place only days after a run in one of the city's parks to commemorate the lives of the Liverpool fans who died in the Hillsborough disaster in 1989.

Ninety-seven football fans were fatally injured in a terrace crush at an FA Cup semi-final between Liverpool and Nottingham Forest on 15 April 1989.

A source told the Mail that the driver appeared to have 'tailgated' an ambulance down Water Street, which had been closed to traffic.

'It looks as if he has panicked when he realised he was in the crowd and people began banging on his car,' the insider said.

'Instead of going back the way he came he's got angry and put his foot down, it's absolutely devastating.'

Mark Leavy told the Mail: 'I will never forget the noise of the people being hit and I will never forget the look on a policeman's face and his uniform covered in blood.

'My God, what he must have seen.'

Patrick Milligan, 25, from Wigan said: 'We all had the best day of our lives watching the parade and then it was like a tsunami within about 5 minutes of the parade finishing. It was horrific.

'The car just swerved into the crowd at speed and everyone was screaming.'

One victim, Jack Trotter, told the BBC from his hospital bed that he was in 'absolute agony' after he was struck by the car.

Mr Trotter, from Newtownards, County Down, had come to the parade from Northern Ireland with his girlfriend, Abbie Gallagher, who narrowly avoided being struck as well.

After being discharged from hospital today, he wrote on Instagram: 'Only back from hospital after the most horrifying incident I've ever experienced in my life... genuinely seriously lucky to still be here after this as I just moved out of the way in time.'

Counter Terrorism Policing North West are assisting Merseyside Police in the investigation. The driver's identity has not yet been released.

Dave Kitchin, head of North West Ambulance Service, confirmed the scale of the response: 'Twenty-seven patients were taken to hospital, including four children. One of the children and another member of the public sustained serious injuries.'

He said several ambulances, plus hazard response teams, the air ambulance and senior clinicians arrived within minutes to treat the casualties.