Some passengers were evacuated and a number of flights have been cancelled at Toronto’s Pearson International Airport Sunday evening after a fire filled part of a terminal with smoke.

Normal operations resumed within a few hours.

Peel Regional Police Const. Akhil Mooken said that the fire started at around 6:30 p.m. and was quickly extinguished but there is a significant amount of smoke and water to clean up.

Mooken said there is “no indication that it was suspicious” but police and investigators were still looking into the cause.

Peel police said on Twitter had received no reports of serious injuries, although paramedics treated “a few patients” for smoke-related injuries and at least one person was sent to hospital.

Pearson airport said at around 9 p.m. Sunday that all flights scheduled to leave Canada for the U.S. from Terminal 1 had been cancelled. Some flights were holding at their gates.

“For passengers scheduled to travel to the U.S. out of Terminal 1 tonight or tomorrow, please contact your airline before leaving for the airport,” the aiport said.

One Florida-bound passenger told local Toronto news station CP24 that airport and airline employees were not helpful.

She said the terminal was filled with smoke for a long period before alarms went off, and that no announcements were made.

“Nobody was helping,” she said.