One passenger suffered a cervical fracture, another broke an arm, while others had bruises in their faces on the flight, Guangzhou-based China Southern Airlines said.
Food and drinks also spilled on passengers during the sudden turbulence 20 minutes after taking off yesterday, Shanghai Daily reported.
Doctors said none of them suffered serious injuries.
The airlines said the turbulence was caused by a strong air current hidden in the clouds that the pilot could hardly notice.