MANILA, Philippines - Asia-Pacific airports and airlines bolstered security Friday and slapped restrictions on carry-on items after Britain disclosed it had foiled a terrorist plot to bomb U.S.-bound flights with liquid explosives.

Long delays, plus dry mouths and dry skin, were likely to be the most immediate result of the new measures, which banned passengers from carrying liquids and gels with them.

Restrictions applied mostly to flights going to the U.S., in line with instructions from Washington. Carriers and airports in Australia, Japan, China, Hong Kong, Taiwan, South Korea, Thailand and the Philippines were among those imposing new rules. Pakistan barred carry-on bags from all flights.

"The potential use of liquid explosives brings a whole new menacing dimension to the terrorist threat," Prime Minister John Howard said in a radio interview.

"It is a reminder sadly to all of us that terrorism is still a very live and menacing threat to the kind of existence that we've all taken for granted," Howard told radio 3AW.

Australia's Qantas Airways said its new restrictions would only apply to flights heading to the United States. But Howard said concerns about liquid explosives could lead to permanent restrictions liquids and gels on hand luggage on international and domestic flights.

Not everyone was worried, though.

Thai Prime Minister Thaksin Shinawatra said there was no reason to panic, and employees at the Indonesian capital's main international airport said everything was operating normally with no boosted security.

"There is nothing to worry about - the terrorists will not come to Asia," Thaksin said.

However, Bangkok's international airport deployed 25 bomb-sniffing dogs and extra security guards with handheld scanners while urging passengers to minimize carry-on items.

A manager at Thai Airways, Suraphol Isaragura na Ayuthaya, said passengers should "refrain from taking liquids, electrical appliances and any kind of gel."

In the Philippines, President Gloria Macapagal Arroyo ordered a high-level security meeting Friday to discuss measures to "intensify intelligence activities" against possible terrorist attacks and to heighten security in all airports, sea ports and other transport terminals, Executive Secretary Eduardo Ermita said.

It isn't the first time that Manila's international airport has had to worry about liquid explosives. A 1995 plot by Asia-based terrorists to use them to bring down a dozen planes led to restrictions on liquids and aerosol products that were later eased.

"The objective is to prevent the entry of liquid bombs," added Andres Caro, a top police official on aviation security, saying U.S.-bound passengers will not be allowed to carry any liquid or gel of any kind or size inside the airplane except for baby formula and essential medications.

Hong Kong's Airport Authority imposed the same restrictions for U.S.-bound passengers and warned people flying on American carriers to show up three hours early for security checks.

Cathay Pacific Airways spokeswoman Carolyn Leung said flights to London from Hong Kong would likely be delayed.

Japan's two main carriers, Japan Airlines and All Nippon Airlines, also said a liquids ban applied to U.S.-bound flights. Airlines in China, and South Korea made a similar announcement. Indian airlines advised passengers not to carry liquids or gels, but stopped short of banning them.

Two security officials at Jakarta's Soekarno-Hatta airport, however, said there were no new restrictions there.

"We heard about the terror plot at London's Heathrow airport, but there are no instructions to raise security procedures here. Everything is going normally," airport police officer Sgt. Franky Reinhart said.