In this Monday, Sept. 22, 2014 photo, a man looks after his wounded relative at a hospital after an explosion at a fireworks factory in Liling in south China's Hunan province.
Two people were also missing following Monday's blast, which shook Nanyang Export Fireworks Factory, the city of Liling in Hunan province said. It revised the injured toll down from 38 because it said five people who had been transferred between hospitals were counted twice.
It did not say what caused the explosion but said it was a work safety incident. The factory is properly licensed, it said.
Workplace accidents are common in China because of lax enforcement of safety regulations, although safety standards are improving.
China is the world's largest producer of fireworks, which are widely used to celebrate the lunar new year. The festival falls in February in 2015.