A fire on a music stage spread into a crowd of spectators at a party Saturday night at a Taiwan water park, injuring more than 200 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 centre.Wang said 83 people had serious injuries and 131 others have light injuries.Taiwan's Central News Agency reported that the fire at the Formosa Water Park in New Taipei City near the island's capital was quickly brought under control.