Media reported four mainland Chinese and two foreigners were among those injured after Saturday's fire, during a party where up to 1,000 revelers were sprayed with colored powder as they danced to music, seeking to escape the summer heat.
The blaze, which broke out around 8:30 p.m. 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 powder, local government official Lin Chieh-yu told Reuters.
"It remains under investigation as to what made the powder explode," he added. Authorities have banned the use of the powder until the investigation is completed.
"The next few days will be a critical time for the injured,"Taiwan Premier Mao Chi-kuo told reporters, adding that 410 people were still in hospital on Sunday, with 194 being treated for serious injuries.
In the immediate aftermath of the explosion, rescuers treated hundreds of people, most of them aged between 20 and 30, wearing wet swimsuits and lying on inflatable plastic doughnuts. Television showed images of people running from sky-high flames.
"There was blood and people were on fire," one injured man said.
No death has yet been reported, but victims of the incident suffered burns to the limbs, with some passing out from the pain while others had burned clothes stuck to their skin, media reports and pictures showed.
"She is young. A student," sobbed the father of an 18-year-old girl with burns on 80 percent of her body, according to television footage.
Soldiers, army vehicles and medical services joined the rescue effort, while hospitals in four municipal precincts, along with Taipei, are treating sufferers.
"We are very sorry about what happened and we will investigate the cause to find out who is responsible," Eric Chu, the mayor of New Taipei City, where the park is located, said on Saturday, adding that it had been ordered to shut down.
The amusement park has been closed temporarily, it said on its website on Sunday. Taipei has sweltered in temperatures exceeding 30 degrees Celsius (86 degrees Fahrenheit) in recent weeks.