Twenty one passengers — including three children — on an Air Canada flight from China have been taken to a Calgary hospital after turbulence caused multiple injuries Wednesday.

Flight 88 was en route to Toronto from Shanghai when the airplane encountered violent turbulence and was forced to stop in Calgary to treat the injured.

Fifteen ambulances were dispatched to the scene as Emergency Medical Services enacted its mass casualty protocol.

21 passengers were taken to a Calgary hospital after a flight from Shanghai experienced violent turbulence 2:20

Passengers were taken through the terminal on stretchers and wheelchairs to waiting ambulances, but EMS officials said all of the injuries were non-life-threatening.

Passengers who were not injured described a frightening scene during the turbulence.

EMS spokesman Stuart Brideaux says 'mass casualty protocol' was enacted as 15 ambulances were dispatched to treat passengers of Air Canada Flight 88. (CBC) An artist who goes by the name Zarum said the turbulence began when the plane was roughly over Dawson City.

"I was laying flat in a business class seat, I had my seatbelt on and suddenly I saw the passenger in front of me go flying up in the air, literally to the ceiling, and then hitting the ground again," Zarum said.

"And then passengers started screaming and objects started flying. It last maybe half an hour."

One passenger, Bing Feng, said she was thinking about her parents and siblings.

Passenger from Air Canada flight AC88, Wednesday afternoon (Meghan Grant/CBC)

"I heard lots of people screaming, like what you would hear on a roller-coaster," she said.

"When you are in the situation, of course [you fear the worst]. You saw all the oxygen masks drop."

Another passenger said it was terrifying.

"I was scared, really scared," Linda He said.

Passenger Bing Feng says she feared the worst following the turbulence on Air Canada Flight 88. (CBC)

Passenger Gord Murray said the crew handled it professionally.

"It was a little scary, but all the crew were professional, handled themselves well, people had minor injuries a little bit shaken up," he said.

"It could have been much worse."

'I was scared, really scared,' said passenger Linda He. (CBC)

A Toronto-based periodontist, in the absence of a medical doctor, assessed roughly 25 injured passengers for head and neck injuries.

"We had certainly been warned to put our seatbelts on numerous times," Dr. Suzanne Caudry told CBC News.

Two people went flying to the ceiling "literally a couple of feet away from me either side. That is because they did not have their seatbelts on," she said.

"Their heads had literally hit the ceiling and actually gone through the plastic ... The fact that nobody was seriously injured is a miracle," Caudry said.

Passenger Gord Murray says the crew handled the situation professionally. (CBC)

The Transportation Safety Board said an investigation will be conducted focusing on the digital flight recorder and the cockpit voice recorder, as well as by interviewing the crew.

John Lee, western regional manager for the safety board, said it hopes to determine "how big a bounce" the plane encountered and whether the turbulence was a surprise event or occurred over a period of time during the flight.

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

The airline said the passenger list indicated there were 332 passengers and 19 crew aboard the Boeing 777-300ER.

Air Canada later moved the passengers from Flight 88 on another Toronto-bound flight, which arrived at Pearson International Airport at 2:48 a.m. ET, according to the website FlightAware.