China Eastern Airlines and other carriers have tightened security checks on flights heading to the United States after a Nigerian man tried to ignite an explosive device on an American passenger plane on Christmas Day.

The Shanghai-based carrier, the only domestic airline that runs direct routes linking the city with the U.S., has banned passengers from carrying any liquid aboard America-bound planes.

However, on other international routes passengers are still allowed to take containers of less than 100 milliliters of liquid in carry-on luggage.

China Eastern is also conducting secondary security checks on luggage at boarding gates.

Foreign Ministry spokeswoman Jiang Yu said China's aviation industry would generally beef up security checks on flights leaving for the U.S..

The Shanghai Airport Authority, operator of the city's two international airports, said yesterday it had received a notice from American transport authorities calling for a beefing up of security checks on U.S.-bound flights.

The tightened checks had not caused congestion at the airports as "those traveling to the U.S. are only a portion of the daily passenger volume," said an airport authority spokeswoman.

Security checks for flights to other countries remained unchanged, she said.

Regular security checks at Pudong International Airport last no more than 10 minutes and the time at its Hongqiao counterpart is no more than 15 minutes.

American Airlines and United Airlines have recommended that passengers arrive at the airports at least three hours before departure.

Their advice came as the U.S. Transportation Security Administration issued new security-screening measures for flights departing from any non-U.S. location to the U.S..

"This measure is in addition to the normal screening that all passengers must complete to enter secured areas," American Airlines said.

Under the new rules, passengers flying into the U.S. will undergo additional security measures at international airports, such as increased gate screening including pat-downs and bag searches.

During flights, passengers may be asked by crew members to stow personal items, turn off electronic equipment and remain seated during certain sections of the trip.

(Shanghai Daily December 31, 2009)