At least 30 people have been injured, five critically after an explosion rocked a busy French carnival.

The incident happened when a ‘Bengal Fire’ display exploded into the crowd at the carnival near Paris today.

Screaming spectators were thrown to the ground as the blasts shook the ground at the popular event, about 11 miles from the centre, close to Charles De Gaulle airport.

At least 30 people have been injured during a blast at a carnival in Paris

The horrific accident in Villepinte, in the French capital’s northern suburbs, saw at least one child suffering horrific injuries when a wooden guy-style figure dubbed Mr Carnival went up in smoke.

The blasts sparked panic among the crowds as several people were harmed by flying debris.

Witnesses described scenes of horror and panicked crowds and reported seeing 'a man with a broken arm' and 'a child with blood on his face'.

Others talked of 'people running around to find their children' in the wake of the explosions.

Screaming spectators were thrown to the ground as the blasts shook the ground at the event

Footage of the aftermath of the blast showed children covered in debris from the explosion

The children injured ranged in age from two to 14, said Nathalie Crespin, spokeswoman for the Paris fire brigade.

‘Many are injured in the face, and all are in hospital in Villepinte,’ said Ms Crespin.

She said the total number of those badly hurt was now 18, with five ‘in a very bad way.’

A few hundred people, including local families, the mayor and other officials, had gathered for the annual carnival in Villepinte and were getting ready to watch its climactic event - the lighting of a traditional bonfire, Crispin said.

Footage from the Villepinte Carnival show flames and plumes of smoke stretching into the sky after the explosions happened at about 6pm

Witnesses reported hearing loud bangs as the fire took hold, just as the carnival parade began

Footage from the Villepinte Carnival show flames and plumes of smoke stretching into the sky

The gasoline used to light the fire was apparently mishandled, prompting the explosion, she said.

Onlookers were hit by chunks of burning wood and suffered primarily from burns.

Crispin and officials from local police and the prosecutor's office of the Seine-Saint-Denis region said the explosion was found to be accidental.

France is in a state of emergency after Islamic extremist attacks in recent years but authorities said there were no signs of arson or terrorism in Saturday's explosion.

The Mr Carvival effigy was almost 20ft high, and had erupted in flames when the Bengal Fire was lit, she said.

‘The kid was screaming and covered in blood,’ said an eyewitness, who added: ‘To begin with, everyone thought the explosion was planned, then we realised something had gone terribly wrong.

‘Bits of the guy and other debris flew towards us in every direction, like spears. The bits of wood were burning hot.

‘People were shouting in panic, and the worst hit were lying on the floor. They had just lit the effigy, and the idea was that it would light up and burn surrounded by flares.’

There were hundreds of children inside the Guy Mousset Stadium, where the carnival was being held to celebrate the start of Spring.

The source said: ‘Many parents lost their children in the mass panic, and were running around trying to find them.’

People ran screaming from the blast as debris covered the watching crowds

The blasts sparked panic among the crowds as several people were harmed by flying debris

Among those hurt was Martine Valleton, the Mayor of Villepinte, who was hit in the right leg.

‘The accident was completely unpredictable,’ said a spokesman for Ms Valleton. ‘She is being treated along with the others injured.’

A ‘Bengal Fire” is meant to involve lots of well-controlled flares lighting up a building or – in this case – the guy.

They can last for up to five minutes, but are banned in many countries because of the dangers involved.

Witnesses described scenes of horror and panicked crowds running from the blast

Festival-goers were setting alight a giant 'Mr Carnival' effigy in the shape of a man, made from straw and sticks.

The so-called Yellow Carnival at Villepinte is used to creating one around an effigy made of wood and straw – both highly inflammable materials.

Despite warnings, hundreds of people including young families were watching as the explosion happened just before 6pm, soon after the carnival parade had started.

An orchestra was playing, and floats that had taken part in an earlier carnival procession were all nearby, prompting fears that the fire could spread.

A spokesman for the local emergency services said: ‘Around thirty vehicles including ambulances and fire engines are at the scene. The emergency is ongoing.’

The cause of the explosion is not yet clear, but it is believed carnival-goers were setting fire to an effigy

By 8.30pm, the area around the stadium had been sealed off by scores of police

By 8.30pm, the area around the stadium had been sealed off by scores of police, and an advanced medical post had been set up to deal with the wounded.

The carnival was evacuated by emergency services who raced to the scene following the dramatic blast.

Local authorities told French media that the blast was 'accidental', and was not terror related.

An aide to mayor Martine Valleton said the explosions were accidental.

'It's an unforeseeable and accidental incident,' the aide said.

Footage from the Villepinte Carnival show flames and plumes of smoke stretching into the sky.