Passengers advised to arrive a half-hour earlier at Pudong and Hongqiao terminals

Security checks have now begun at the entrances of Shanghai's two international airports as part of the implementation of a national anti-terrorism law.

As of Monday, all people and their belongings must clear checks at the entrances of Shanghai Pudong International Airport and Shanghai Hongqiao International Airport - as well as pre-departure checks, an airport official said.

They became the first airports in China to implement additional checks required by the new law.

Officials advised passengers to set aside an extra half-hour in their travel schedules.

The newly launched checks will be similar to existing security checks at airports, focusing on passengers' carry-on baggage, searching for such items as knives, flammable and explosive products and guns.

In addition to the previously existing security check area, another 27 checkpoints at Pudong airport's entrances and 14 at Hongqiao airport entrances have been added, with four staff members assigned to each checkpoint.

The tightened security measures comes on the heels of the nation's first anti-terrorism law, which took effect on Jan 1, according to Xia Gongwei, an official from Pudong airport.

Under the law, security checks should be made of people and objects in large, busy areas like airports, railway stations, ports, metro stations, long-distance bus stations and customs.

Shanghai's airports are the first and only ones in the country so far that have responded to the new law's requirement, said Su Weiwei, an official from the Shanghai Airport Authority.

No other airport has announced similar measures, causing some media outlets to call Shanghai the city with "the tightest security check airports" in China.

Xia said it is "the first time for Shanghai's airports to increase anti-terrorism security checks outside the security clearance area - which is to make sure of the safety of the public area of the airports".

On Monday morning, there was no sign of passenger complaints, as most people made it through the additional checks without a delay and only a few were required to open their suitcases for further inspection.

"I completely understand the increased checks at the airport, and I also heard that there was a blast that happened months ago," said a woman surnamed Guo. Guo and her daughter were on their way to Xiamen, Fujian province, after visiting Shanghai Disney Resort.

Mike Zeng had to give up his hair spray after the airport staff told him it was explosive.

"I see the point for the security check, and totally understand," he said.