A security issue at Toronto’s Pearson airport grounded international flights and prompted a call to Peel police Saturday morning.

Few details were made available to the public on what the Greater Toronto Airport Authority (GTAA) is calling a security breach.

The incident happened at 7:52 a.m. on Saturday in Terminal 1 where international flights and flights to the U.S. depart.

Peel police were called to the scene after a pocket knife was discovered in a passenger's carry-on luggage on board a plane. The knife was handed over to the flight crew.

"The laws in the U.S. have changed to allow pocket knives on planes," said Peel Police Constable Thomas Rattan. "However they are not allowed on Canadian planes."

Between the initial discovery of the pocket knife and 9:15 a.m. all flights out of the terminal were grounded.

“It’s not uncommon. It doesn’t happen quite that often though,” said Natalie Mohamed, a senior communications advisor for the GTAA. “We have a good working relationship with the Peel police and they’re always quick to respond, so it does not often affect operations.”

According to the airport’s website, seven flights were cancelled, but Mohamed was quick to note that this number may not be directly correlated to this incident.

No arrests were made and operations at the airport are returning to normal.

Alongside the delays from the security breach were delays getting through U.S. customs.

According to the GTAA, labour troubles between U.S. border agents and the American government caused long line-ups.

Border agents are upset over recent budget cuts handed down from Washington.

Travellers are being told to give themselves plenty of extra time for check-in and customs.