Don't panic if you hear what sounds like gunfire at the Calgary International Airport tonight — officials are planning a security-training exercise.

The Calgary Airport Authority is alerting travellers of their plans to conduct the mock scenario between 9 p.m and midnight, noting the exercise will involve simulated gunfire and emergency vehicles responding to the scene.

"There will also be a number of volunteers who will be in makeup with simulated injuries within the terminal building during this period," the airport authority said in a release.

The exercise is planned for an isolated area within the terminal building, but travellers may still hear unusual noises or see participants responding to the simulated situation.