Drivers of Greyhound buses are restricting carry-on bags as a safety measure after last month's killing of a male passenger in Manitoba, the president of Local 1374 of the Amalgamated Transit Union said Monday.

"It's up to the discretion [of the driver], but I believe everybody is taking action," said Jim Higgs in Calgary.

Higgs added that he informed drivers of the measure in a bulletin over the weekend.

"They have broad ability to restrict or deny carry-ons."

That means bus drivers can force passengers to put their bags in the belly of the bus, except for medicines, baby-related items and books, he said.

The union and the company have formed a subcommittee to address safety and security measures on buses after Tim McLean was stabbed multiple times and beheaded on a Greyhound bus near Portage la Prairie on July 30, Higgs said.

Vince Weiguang Li, 40, appeared in court in Winnipeg charged with second-degree murder and ordered to undergo psychiatric assessment earlier this month.

Greyhound spokeswoman Abby Wambaugh said since the Sept. 11 attacks in the U.S., the company has reserved the right to store passenger bags underneath the bus and to remove any potentially dangerous cargo at the driver's discretion.Recent physical searches of bags by some drivers have turned up knives and drugs in Edmonton, Higgs said.

"The knives and weapons are major concerns," he said.