Canadian officials have banned most carry-on luggage for U.S.-bound passengers following a failed Christmas Day plot to blow up a plane flying from Amsterdam to Detroit.
Transport Canada said Monday that passengers may only carry medical devices, small purses, cameras, laptop computers, canes, walkers, diaper bags, musical instruments and bags containing "life-sustaining items."
Travelers headed for the United States have been allowed to carry on only one bag since Saturday, following 23-year-old Nigerian Umar Farouk Abdulmutallab's alleged attempted to bring down a Northwest Airlines flight as it prepared to land in Detroit on Friday.
Transport Canada said it is trying to alleviate backlogs at security checkpoints, after passengers complained of chaos and long lines at Pearson International Airport in Toronto over the weekend and Monday morning.
Police are now helping with security at four of Canada's biggest airports after Transport Canada requested assistance.
Police are performing a secondary search of passengers after they pass the main security check point at airports in Toronto, Montreal, Calgary and Edmonton, Alberta. About 40 Royal Canadian Mounted Police officers are doing searches at Pearson.
Transport Canada spokesman Patrick Charette said the measures are expected to remain in place for at least several days.
"We hope the restrictions on those carry-on baggage will help to assure the effectiveness and efficiency of security screening," Charette said.