A security guard screens a Greyhound passenger at the Calgary terminal Wednesday. (CBC)

As the holiday travel season ramps up, Greyhound Canada announced it has begun screening passengers at major terminals with hand-held security wands.

The company implemented new security measures Tuesday at its Edmonton, Calgary and Winnipeg terminals, with other locations to follow starting on Dec. 15.

All luggage must now also be stored under the bus, with exceptions for essential travel items such as medications, baby formula and wallets, said Abby Wambaugh, a Greyhound spokeswoman from Dallas, Texas.

"This is something that has been at drivers' discretion and now it's mandatory that all luggage be stowed underneath the coach," she told CBC News.

Security guards will do the screening with the metal detector wands, she added.

Greyhound is not publicly releasing other security details that are in place.

"If we release them, they would no longer be effective," said Wambaugh.

"We're trying to make this as smooth a transition as possible," she added, acknowledging she is not sure if there will be delays because of the new measures.

The new measures follow a two-year security study, said the company.

"We hope to set an example for other carriers to follow. Yet, the high cost of implementing such a program should not fall squarely on the shoulders of the private sector, so we will continue to advocate federal support for bus security funding," Stuart Kendrick, Greyhound Canada's senior vice-president, said in a statement.

A list of restricted and prohibited items posted on the Greyhound Canada website includes firearms, ammunition, animals, flammable liquids and fruit.

In August, Winnipeg resident Tim McLean was killed on a Greyhound bus west of Portage la Prairie, Man. A fellow passenger, Vince Li, is charged with second-degree murder.