HONG KONG - Five Hong Kong women are being treated in hospital in Taiwan after they were caught up in the weekend's fire at a water park.

The women, aged between 18 and 25, suffered burns, the Immigration Department of Hong Kong Special Administrative Region said, adding that it had sent four officers to the island to help the victims' relatives.

In total, almost 500 people were injured in the fire in New Taipei City and more than 400 of them, many seriously burned, were still in hospital as of Sunday night. More than 180 were in intensive care.

The fire late Saturday was sparked by an accidental explosion of a colored theatrical powder thrown from the stage in front of about 1,000 people, the local fire agency and media said.

The exact cause of the fire was still being investigated. Taiwan's leader Ma Ying-jeou visited burn victims at a hospital in Taipei on Sunday afternoon and said authorities would do their best to ensure victims receive "the best medical care" and find out who was responsible for the "tragic incident."