WINNIPEG, Manitoba -- Greyhound is tightening security at its major Canadian bus terminals, including screening passengers with hand-held metal detectors.

The beefed-up security comes roughly five months after a horrific attack in which a man was beheaded by a fellow passenger on a Greyhound coach near Portage La Prairie, Manitoba.

The new measures do not stem directly from that event, according to a Greyhound spokeswoman, but are the result of a two-year study aimed at improving security.

"Once we completed that study over the summer months, we began to review ... and figure out which specific security measures would be most effective," said Abby Wambaugh of Greyhound.

"We believe these measures that were implementing make the most sense and will be the most effective at this point in time for our type of transportation," Wambaugh added.

Passengers are being screened with a magnetometer for weapons and required to stow their luggage in the baggage bays rather than take on board, the company said.

Greyhound said it would take other security steps that it was not announcing publicly.

The new measures began the middle of December at company terminals in Calgary and Edmonton, Alberta, and Winnipeg.

In the Manitoba incident, a man who brought a hunting knife onto a bus launched an unprovoked attack on a man sleeping next to him, cutting off the victim's head and displaying it to other horrified passengers. Police eventually took him into custody.

Greyhound currently conducts hand metal-detector screenings at random terminals in the United States.

The company did not release the cost of the increased Canadian security but said it was "several million dollars" and was hoping the Canadian government would pick up part of the tab.