The number of party revellers injured in a fire at a Taiwan water park was put at 498 yesterday as authorities began investigating the cause, suspected to be a sudden explosion of a coloured powder thrown on those attending the party.

Six foreigners and seven visitors from Hong Kong, mainland China and Macau were among those injured after about 1,000 people dancing at Saturday night’s event were sprayed with the powder, as a special feature of a festival also held in previous years.

The figure released late yesterday by local authorities was lower than an earlier estimate of 519 injured due to patients being transferred between hospitals and being double-counted, a government official said.

The blaze, which broke out at around 8.30pm at the Formosa Fun Coast water park on the outskirts of the capital, Taipei, is suspected to have been caused by an explosion of the coloured powder, local government official Lin Chieh-yu told Reuters.

Silhouettes of people running from a blaze are seen at the Formosa Fun Coast water park, on the outskirts of the capital, Taipei in this still image taken from a video shot early yesterday.

“It remains under investigation as to what made the powder explode,” he said.

Authorities have banned the use of the powder until the investigation is completed and its safety can be assured.

“The next few days will be a critical time for the injured,” Taiwan Premier Mao Chi-kuo told reporters. All of the 498 injured were still being treated in 43 hospitals across the island, according to the latest figures provided by the New Taipei City government.

In the immediate aftermath of the explosion, rescuers treated hundreds of people, most of them aged between 20 and 30, who wore wet swimsuits and lay on inflatable plastic doughnuts.

There was blood and people were on fire

A video posted online by Apple Daily showed dancers in front of the stage engulfed in clouds of coloured powder a moment before a fireball erupted, followed by pockets of flame, triggering panic and screams. “There was blood and people were on fire,” one injured man said.

No death has yet been reported, but victims suffered burns on limbs and torsos, with some passing out from the pain while others had burned clothes stuck to their skin, media reports and pictures showed.

“Her whole life is ruined,” sobbed the father of Chu Li, an 18-year-old girl with burns on 80 per cent of her body, during a visit by President Ma Ying-jeou to victims in a Taipei hospital.

Soldiers, army vehicles and medical services joined the rescue effort, while hospitals in four municipal precincts, along with Taipei, are treating sufferers.

The amusement park has been closed temporarily, it said on its website yesterday.

Taipei has sweltered in temperatures exceeding 30 degrees Celsius (86 degrees Fahrenheit) in recent weeks.