Authorities said that two gunpowder warehouses within the factory area posed a high risk amid rescue efforts, state media reported.
Rescue teams had to evacuate everyone within a 3km (1.9mi) radius of the fireworks plant. They also implemented measures like humidifying the area to “prevent secondary accidents during the rescue”.
The impact of the blast was so destructive that windows of a residential building near the factory were also shattered, a CCTV reporter noted in a televised broadcast from the scene.
The ages of the injured range from their 20s to 60s, and some suffered bone injuries after being hit by flying debris, said the CCTV report.
President Xi Jinping has urged all-out efforts to search for people who are still unaccounted for and save the injured. Xi also called for an investigation into the accident to hold those responsible to account, state media reported.