Toronto/New York/Washington, Dec 25 (IANS) Beverage containers also came under the scanner at US and Canadian airports from Friday as the North American countries further tightened aviation security.

The Canadian Air Transport Security Authority followed the US Transportation Security Administration (TSA) which enforced these measures for passengers boarding flights in the country.

The TSA warned Friday that insulated drink containers will be checked at airport security checkpoints as terrorists could use them to hide explosives.

The new advisory applies to thermoses and cups whether or not they contain any liquids.

It also reminds airline passengers that the ‘3-1-1 rules’ for liquids remain in effect for carry-on bags. This states that liquids or gels must be in containers holding no more than three ounces; that such containers must be placed in a clear, one-quart zip-lock bag; and that travellers are limited to one such bag apiece.

US airports are expected to receive some 43 million travellers during the winter holidays, according to the Air Transport Association of America.

The tough measures come into force exactly a year after an Al Qaeda-linked Nigerian man tried to detonate explosives on a Northwest flight from Amsterdam about to land at Detroit on the eve of Christmas last year.

‘The possible tactics terrorists might use include the concealment of explosives inside insulated beverage containers, so in the coming days, passengers flying within and to the US may notice additional security measures related to insulated beverage containers,’ the TSA said.

The notice is based on intelligence and is indefinite, it said.

In response to terrorist threats, the TSA now gives airline passengers two choices: Get a full-body scan using low-dose radiation that shows a naked image – everything from head to toe. Or refuse the scan and have a TSA official run his or her hands over every part of your body.

Some 500 of the controversial ‘Advanced Imaging Technology’ scanning machines for passengers have been deployed at more than 75 US airports, and additional steps have been taken to screen cargo shipped by air or checked by passengers.

The Canadian Air Transport Security Authority responded to the US step by introducing the measures at all airports.

Passengers bound for the US already undergo additional screening, including removal of shoes, at Canadian airports.

The Canadian Air Transport Security Authority said it ‘now requires all passengers to remove insulated beverage containers from their carry-on baggage and place them in a bin for inspection’.

Canada, which is very sensitive to the US skepticism about its security regime, had introduced physical searches of passengers and banned carry-on bags last year after Al Qaeda’s Christmas Eve bid to blow up the Northwest flight.

These additional measures led to chaos at Canadian airports. Similar scenes could be repeated at Toronto airport, one of the busiest airports in North America which handles 33 million passengers a year.

(Gurmukh Singh can be contacted at gurmukh.s@ians.in)