Passengers heading to the United States from Vancouver faced long delays at the airport. (CBC)

Travellers flying to the United States from Vancouver can expect major delays over the next few days.

Airports across North America have increased security measures after an unruly passenger was arrested aboard a Northwest Airlines flight to Detroit from Amsterdam on Sunday, following an attempted attack aboard a plane with the same flight number Friday.

The increased security screening "is going to take a long time," WestJet spokesperson Robert Palmer said. Delays could be as long as four hours, he said.

Airport officials said anyone flying to the U.S. will face secondary screening, including a pat down and a check of their personal baggage.

Passengers are allowed to bring aboard only one piece of carry-on luggage. WestJet and Air Canada will both waive excess-baggage fees.

Paymaneh Chychi, who flew home to Vancouver from San Francisco on Saturday, faced long delays before being allowed to board a plane.

"The thought of not getting home was a little bit scary and a little bit teary," she said.

Donna McMullen, heading to Phoenix from Vancouver, showed up an extra hour early for her flight. "I'm glad they're having the extra security," she said.

The increased security measures caused delays throughout the country, including airports in Calgary, Edmonton, Winnipeg and Toronto. Those measures are expected to be in place for several days.