All departing and transit passengers at Hong Kong International Airport will have to place drinks and liquids in transparent plastic bags for screening under tough new security measures to be implemented next month.

The measures, recommended by the United Nations' International Civil Aviation Organization, are in response to what are perceived to be increased threats from terrorists using liquid explosives to attack aircraft.

"As Hong Kong is an aviation hub, we're obliged to follow their [ICAO] recommendations," Simon Li Tin-chui, chief operations officer of security at the Civil Aviation Department of Hong Kong SAR Government, said on Feb. 27. "Additional security measures will impact on passengers, but we're liaising with parties to make sure sufficient resources [are in place] and preparatory work is done to ensure smooth operations."

The extra precautions will come into force March 21 and continue until further notice.

Li advised travelers to expect delays, particularly during the initial stages of the operation.

John Lamond, head of safety, security, and environmental and planning services with the Airport Authority Hong Kong, urged travelers to consult their airlines and relevant Web sites for up-to-date information.

All liquids, gels and aerosols in hand baggage will have to be carried in containers with 100-milliliter limits. Liquids, gels and aerosol containers in excess of 100 milliliters will be restricted even if the container is partially full.

All passengers will be required to place their containers in a transparent, re-sealable plastic bag that should not exceed one liter capacity. Each passenger will be limited to one bag, which will be screened separately.

Liquids, gels and aerosols in excess of 100 milliliters should be placed in hold baggage. Passengers who breach the limit for carry-on baggage will be refused entry in restricted areas.

The measures will affect all outgoing passengers, as well as transit passengers who will be re-searched before boarding their transfer planes.

After clearing security checkpoints, liquids, gels and aerosols purchased at departure halls will be subject to regular duty-free limitations and conditions.

Exemptions will be made for medications and special dietary requirements such as baby milk and diabetic supplements. Travelers are advised to provide medical certificates and other documents of authenticity.