A sunny morning in Southampton quickly descended into chaos after a shock explosion saw hundreds evacuated from the city’s largest shopping centre.

Staff and shoppers at Westquay ran for cover at around 9.30am on Wednesday after a van carrying gas cannisters was engulfed in flames before it exploded and a fireball rose into the sky from outside the entrance to the Podium car park on Harbour Parade.

A plume of thick black smoke floated across the Southampton sky, visible across the city.

Minutes after the explosion, emergency alarms sounded throughout Westquay and the car parks directing all staff and shoppers to leave the huge shopping complex as soon as possible.

The explosion had erupted from the back of a van directly outside the entrance of the Podium car park.

The flames were as high as the balcony above the car park at the fire's peak, with the heat damaging the signs above the car park entrance

Emily Robinson was at the train station on her way to work when she heard a loud bang. She said: “It is a big pillar of smoke. It looks like quite a large fire.

“There seemed to be at one point a big bang. That could have come from the fire.

“There was a fire engine that came down at speed past the bus I was on.

“I was just wondering what was really going on.”

Eye witnesses watched on when the truck exploded Eye witnesses watched on when the truck exploded (Image: NQ) Three fire crews were on the scene shortly after the loud explosion was heard and began tackling the large fire ball – with flames reaching the outside balcony of the shopping centre, directly above the carpark.

Crowds quickly began to gather and watch on as firefighters deployed their hose jets and began to douse the large flames with water.

One of those gathered was delivery driver Sheikh Emad Uddin Billal.

He told the Echo: "I noticed a car on fire with a crowd of people watching - I stopped my motorcycle and took a video. As a delivery driver I always pass this way."

Fire crews from Hightown, Redbridge and St Mary’s worked hard to try and get the blaze under control.

A small section of the bushes and shrubs outside the car park also began to catch alight but were quickly put out by Hampshire Fire and Rescue.

Firefighters led a snaking trail of hosepipes down Harbour Parade with water used the battle the scorching flames pooling on the road.

Harbour Parade was blocked off by police Harbour Parade was blocked off by police (Image: NQ) Just before 11am, Hampshire Fire and Rescue said in a statement: “Crews from St Mary’s, Redbridge and Hightown are currently in attendance at a vehicle fire following reports of smoke and flames at the back of Westquay, Southampton at just after 9.30am this morning.

"People are asked to avoid the area while emergency services deal with the incident. Harbour Parade is closed in both directions."

A spokesperson for Hampshire Constabulary added: "This was a vehicle fire on Harbour Parade, reported at 9.37am.

"The fire service are leading on this incident and police are assisting with road closures."

Harbour Parade was closed in both directions by police as firefighters worked to get the ball of flames under control.

Lifelong Southampton resident John White said he was walking across the bridge from Southampton Central train station when he heard a huge explosion.

READ MORE: Westquay van fire: Acculine issues statement after explosion

He said: "As I was walking towards the shopping centre, I could see a huge plume of smoke.

"When I turned at the corner, I could see flames reaching the balcony floor around Westquay.

"It was quite shocking as I only came into town to grab a coffee and didn’t expect to see such an emergency response.

"As I started to approach the road, emergency services were on the scene.

"The bang that was so loud it makes me wonder if the truck was carrying some sort of flammable or explosive equipment."

READ MORE: Westquay van explosion: Fire service confirms cause

By 11.30am, firefighters had managed to put out the majority of the flames, with firefighters continuing to flood the wrecked truck with water.

Hampshire Fire then issued another update and stated: “The fire is now out but there remains smoke in the area and crews are currently working to clear this.

“We expect to have a presence on site for some time until the incident is fully resolved.

“The road closure remains in place. We thank everyone for their patience while we deal with this matter.”

Plumes of smoke could be seen across the city Plumes of smoke could be seen across the city (Image: Jack Glennie) Around ten minutes after the fire service issued its latest update, the roundabout on Harbour Parade was reopened by police – with many drivers visibly shocked at the emergency scene.

Westquay shoppers soon began gathering around the doors to the shopping centre, hopeful that they would soon be allowed back inside.

At noon, all fire engines left the scene, with the area around the car park entrance still cordoned off.

The shopping centre security were left telling disgruntled shoppers outside the centre, that Westquay would remain closed for at least another hour.

Hampshire Fire & Rescue Service confirmed at around 12.30pm that the blaze was an accident.

Westquay was evacuated while firefighter dealt with the blazeWestquay was evacuated while firefighter dealt with the blaze (Image: Jack Glennie) A spokesperson said: "This morning, crews responded to a significant vehicle fire at Westquay Southampton.

"The incident, which began just after 9.30am, involved a vehicle containing cylinders that exploded.

"Fire crews from St Mary’s, Redbridge, and Hightown attended the scene, using three jets and three hose reels to bring the blaze under control.

"The fire completely destroyed the vehicle and caused heat and smoke damage to the entrance of the Westquay car park.

"Ventilation fans were deployed to clear the remaining smoke.

"The fire has been confirmed as accidental, and the scene has now been handed over to the police.

"We would like to thank everyone for their patience and cooperation during this incident."