A Canada-bound airliner was forced to make an emergency landing after severe turbulence injured 21 passengers, including three children, officials said.
The Air Canada flight from Shanghai to Toronto was diverted to Calgary after the turbulence hit.
Eight passengers suffered neck and back injuries and 13 more were taken to hospital for observation.
The injured were in a stable condition, an emergency services spokesman said.
Bing Feng, a passenger, described hearing "lots of screaming" as the plane became "like a rollercoaster".
Another passenger, Yi Lee, said: "To start with it was just OK, normal just up and down, and all of a sudden it was really violent and just shaking everybody.