350 injured as fire hits Taiwan water park party
RALPH JENNINGS, Associated Press

TAIPEI, Taiwan (AP) — A fire on a music stage spread into a crowd of spectators at a party Saturday night at a Taiwan water park, injuring about 350 people, authorities said.

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

Taiwan's Central News Agency reported 349 have been injured, quoting the Health Ministry. They included four mainland Chinese and two foreigners.

Wang said 83 people had serious injuries.

The stage caught fire at the Formosa Water Park in New Taipei City near the island's capital and 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.

CNA reported witnesses as saying 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.

-- (c) Associated Press 2015-06-28

Looks like it was a dust explosion.
This is when seemingly innocuous and harmless substances like everyday flour used to make bread can become explosive fireballs when the powder is suspended in air and ignited.
In order for a dust explosion to occur, it has to satisfy all the components of what they’ve named the “explosion pentagon.” Essentially, what you need is: a cloud of dust suspended in the air in an enclosed space where there is some kind of ignition. And all these requirements can be fulfilled at mills and storage facilities. Even transporting flour is a risk, because the smallest flame or spark can trigger the explosion.
Over 130 years ago, a flour mill in Washburn, Minnesota exploded, leading to the deaths of 18 people. Since this tragedy, the industry has worked hard to try to cut down the risks. Yet in the nine-year period between 1994 and 2003, there were 115 dust explosions in the US agriculture and food processing industries. Most of the incidents involved grains, and many of them claimed lives.
http://scribol.com/science/the-tremendously-explosive-power-of-flour

Here's a video of a cloud of bread flour being ignited:
https://youtu.be/-QamkInLL38?t=1m