Scene of the fire.

TAIPEI - A fire on a music stage spread into a crowd of spectators at a party Saturday night at a water park in Taiwan's New Taipei city, injuring more than 400 people, authorities said.

An accidental explosion of an unknown powder set off the fire near the stage in front of about 1,000 spectators, said Wang Wei-sheng, a liaison with the New Taipei City fire department command center.

By 3:40 am, 463 injured people had been rushed to hospitals, according to the Central China Television (CCTV). Among them, 456 are from Taiwan, 3 from Chinese mainland, 3 from other countries and regions and 1 unidentified yet.

The fire broke out at about 8:30 pm at the main stage of the Formosa Water Park, which was having a Color Play Asia party. The fire was quickly brought under control.

Video showed rescue workers and bystanders carrying burned and injured people on their backs, in inflatable boats and on stretchers to get medical treatment.

Witnesses said the fire spread quickly after the colored powder was blown into the air.

It wasn't clear if the colored powder was part of a performance. The cause of the fire is being investigated.

This is the worst incident of mass injury in the history of New Taipei city.