Fire engulfed the shop sending plumes of smoke into the air, video footage circulated on social media showed.
The fire had since been put out, Hangzhou’s West Lake District Information Office said on its official microblog.
The injured were taken to hospital, it said, adding that 12 were seriously hurt.
Authorities were investigating the cause.
Explosions and other mishaps are common in China, often because of patchy enforcement of safety rules. The central government has pledged to improve checks to avert such accidents.
(By Cheng Fang and Ryan Woo; Editing by Robert Birsel)
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