SEATTLE (Reuters) - An Air Canada jet made an emergency landing at Seattle-Tacoma International Airport on Thursday and passengers were safely evacuated, according to an airport spokesman.

The crew aboard the Bombardier Inc Dash 8 plane reported seeing light smoke inside the cabin on the plane’s scheduled flight to Seattle from Calgary, and declared an emergency before landing at the airport without injuries, according to airport spokesman Perry Cooper.

Calgary resident Heather Hudson, 53, said she was a passenger on the flight and described a mild-smelling smoke appearing at the front end of the cabin and slowly filling the rest of the plane shortly before landing.

Flight attendants worked quickly to check the overhead bins for the source of the smoke, but did not appear to find it, Hudson told Reuters via Twitter direct message.

The mood aboard was subdued but tense during the incident, Hudson said, as crew members announced that an emergency had been declared. Some passengers quietly prayed before landing, she added.

Airport crews were notified of the emergency about 15 minutes before landing, Cooper said.

He added that the cause of the smoke is under investigation. He declined to say how many passengers were evacuated.

The Dash 8 is a short- and medium-range turboprop plane which can carry between 37 and 86 people, depending on the model, according to Bombardier’s website.

Representatives from Air Canada did not immediately respond to requests for comment.