Norad said fighter jets, including CF-18s, escorted two international flights bound for Montreal on Wednesday due to a “security incident” that prompted a police response at the Trudeau International airport.

The binational organization that monitors and defends airspace in North America told CTV News that CF-18 and F-16 fighter jets, as well as KC-135s aerial refuelling tankers, “monitored the situation until the involved commercial aircraft landed safely at destination.”

When the planes landed, Quebec provincial police arrested two male passengers in their 20s and 30s. The Sûreté du Québec (SQ) said the men are being questioned by investigators and “could face charges related to fraud,” according to SQ spokesperson Béatrice Dorsainville.

No further details about the men were released by police.

Meanwhile, Norad did not provide any further details.

“Norad employs a layered defence network of radars, satellites, and fighter aircraft to determine appropriate responses to air security incidents and ultimately to keep Canada and the United States safe each and every day,” a spokesperson said in an email.

The Montreal airport also said that the discovery of a suspicious suitcase on one of the landing flights led to the closure of one of the two runways.

The incident prompted NAV Canada to limit the number of incoming flights “due to a potential security situation at the airport,” a spokesperson said.

Later in the afternoon, Eric Forest, an airport spokesperson, told CTV News that the potential threat in the suspicious package turned out to be unfounded and that operations returned to normal.

“The investigation is still ongoing, but there is currently no threat to the safety of the traveling public at YUL,” Forest said, adding that the incident caused some delays for domestic and international flights.

FAA grounded all flights to Montreal

As the incident unfolded, the Federal Aviation Administration (FAA) grounded all flights to the Montreal international airport “due to bomb threat,” a notice on its website stated on Wednesday.

The ground stop was issued at 3:02 p.m. but was lifted shortly before 5 p.m., when the mention of the alleged bomb threat was removed.

Montreal police say they responded to the airport and assisted Quebec provincial police, which has taken the lead on the investigation.

The airport said passengers are urged to check their flight schedules before heading to Trudeau airport due to possible delays.