Hundreds of travellers were stranded in Pearson airport's terminal one Thursday after an employee opened a door the wrong way, an aviation source told CBC Toronto.

Roughly 200 passengers who had arrived at Pearson from various parts of Canada in the early morning ended up in the wrong area of the airport as a result of the error, the source said, causing confusion with U.S. Customs and Border Protection.

Multiple connecting flights to the U.S. were delayed while officials tried to sort out the issue.

"Toronto Pearson and U.S. Customs and Border Protection are working with airlines to identify flights that can board," the airport said through its official account on X, formerly Twitter.

"Airport operations in T1 domestic, international and at our T3 gates remain unaffected."

Several travellers who appeared to be stuck in terminal one expressed frustration in posts on X about what they said was a lack of communication from officials about the situation.

In a statement, a spokesperson for Lynx Air said the mistake was made by a worker with a separate ground services operator that is accountable for gate services once our aircraft lands.

"We are actively in contact with both the GTAA and the ground handling company to investigate what has happened and how this situation could have occurred."