Smoke is shown inside the security screening area of Terminal 1 at Pearson International Airport in Toronto on Sunday, March 17, 2019. A fire at Canada's busiest airport has led to cancellations, delays and a few smoke-related injuries. The blaze broke out Sunday evening in Terminal 1 at Toronto Pearson International Airport, leading authorities to evacuate the area. It was extinguished a short time later, but the airport announced in a tweet that all flights to the U.S. scheduled to depart from Terminal 1 had been cancelled. THE CANADIAN PRESS/HO - James Agnew

TORONTO - Chaos erupted at Toronto Pearson International Airport on Sunday evening after a fire near a security checkpoint led authorities to evacuate the area, but within a few hours operations were starting to return to normal.

All U.S.-bound flights from Terminal 1 at Canada's busiest airport were cancelled for the rest of the night, Pearson Airport announced on Twitter.

"We thank passengers for their patience as we put safety first," a post from the airport's official account read, adding that outbound international and inbound arrivals processing had resumed just after 10 p.m.

"Please check your flight status with your airline before leaving for the airport," it also cautioned.

The blaze broke out around 6:30 p.m. and was extinguished a short time later.

Photos posted on social media showed thick smoke in parts of the airport, and television footage showed frustrated passengers crowding the terminal's main concourse.

Paramedics said one woman was taken to hospital in stable condition while another was treated at the scene and released.

Police said no major injuries were reported and crews were working to clean up damage from smoke and water.

Meantime, dozens of inbound flights were stranded on the tarmac for hours as crews worked to ensure the terminal was safe for re-entry.

One passenger arriving from Barbados tweeted that there were 22 planes ahead of hers.

"Will be a long night at YYZ," Heather Bailey wrote on Twitter.

Duncan Smit, a Dutch businessman who had been in Vancouver for a conference, told The Canadian Press that his flight home to Amsterdam had been delayed by several hours.

"There was a lot of smoke in part of the terminal," Smit said in a phone interview from his gate at Pearson, where he had been waiting since Sunday morning after arriving from Vancouver.

But Smit was taking the delay in stride.

"Those three, four, five hours that I have to wait, well so be it. I'll get another cup of coffee," he said.

There was no immediate word on what caused the fire.

News from © The Canadian Press, 2019