More than 200 people were injured, over 80 of them seriously, in an explosion at a water park outside Taiwan’s capital Taipei Saturday after coloured powder being sprayed onto a crowd ignited, officials said.

Footage on the Apple Daily newspaper website showed crowds dancing as music played and clouds of powder being sprayed out which suddenly turned into a ball of fire that swept through the spectators.

“Our initial understanding is this explosion and fire… was caused by the powder spray. It could have been due to the heat of the lights on the stage,” said a spokesman for the New Taipei City fire department.

The municipality’s deputy mayor said 221 had been hospitalised, with fire officials earlier saying 81 had been seriously injured.

Local media reported that 97 people were seriously hurt.

The blast happened as hundreds gathered for an event at the coastal Formosa Fun Coast waterpark, just outside the capital Taipei.

Television images showed the stage on fire and crowds running away, some of them only dressed in swimwear and covered in coloured powder.

The fire was quickly extinguished, officials said.

One male witness told local news channel CTI: “It started on the left side of the stage. At the beginning I thought it was part of the special effects of the party but then I realised there was something wrong and people started screaming and running.”

Media reports said some victims had suffered burns to more than 40 percent of their bodies.

A doctor treating 41 victims at one hospital in Taipei said 17 of them were “seriously burned”.

“They all had respiratory system damage,” he said.

Dazed victims were carried from the site on inflatable rubber rings and others were lying on inflatable water toys with bystanders pouring water over them from plastic bottles.

Authorities said that ambulances had struggled to get near to the site and had to send in emergency workers with stretchers.

“We feel sad and regretful about the accident,” New Taipei Mayor Eric Chu told reporters.

He said that extra doctors had been called in to help treat the victims.

“I’ve ordered the park to shut down immediately and be placed under a rigorous investigation,” he added.