The fire late Saturday was sparked by an accidental explosion of a coloured theatrical powder thrown from the stage in front of about 1,000 people, the local fire agency and media said.
The powder for the one-time event called "Color Play Asia" ignited along the ground, mainly burning people's lower bodies, said Wang Wei-sheng, a liaison with the New Taipei City fire department command center.
The exact cause of the fire was still being investigated, but Taiwan Premier Mao Chih-kuo banned public activities that use the colored powder.