At least eight passengers on an Air Canada flight were injured Wednesday after turbulence rocked the aircraft, causing pilots to make an unscheduled stop in Calgary, the airline said.

The jet landed safely at Calgary International Airport. Twenty-one passengers were taken to area hospitals, eight with injuries and 13 for observation, Air Canada said.

The Boeing 777-300 ER with 332 passengers and 19 crew aboard was flying from Toronto to Shanghai when the rough ride prompted the landing at 3:23 p.m. local time (5:23 p.m. ET), Air Canada said.

"Our focus today has been on those passengers who have been injured in this incident and those other passengers on the aircraft for whom this has been a very unsettling experience," Klaus Goersch, executive vice president and chief operating officer at Air Canada, said in a statement.

"Safety is always our first priority and so any incident involving the safety of our passengers and crew is of utmost concern," Goersch said.

Video taken by CTV showed one person being wheeled out on a gurney. Alberta Health Services spokesman Stuart Brideaux said that three children were among the 21 taken to hospitals. Seven adult passengers showed signs of potential neck or back injuries, he said.

"A full investigation of the incident is being undertaken," Air Canada said.