Airports of Thailand (AoT) on Monday tightened up security at Suvarnabhumi and Chiang Mai international airports on Monday following the arrest of a Swedish- Lebanese terror suspect allegedly linked with Hezbollah, a Shiite terrorist organization.

Security had been increased from level two to level three at the two airports, while security at four other international airports -- Don Mueang, Phuket, Hat Yai and Chiang Rai -- remained at level two, AoT president Aniruth Thanomkulabutr was quoted as saying by the website of Bangkok Post.

More security staff would be deployed while more frequent and strict checks on passengers, airport areas and luggage would be conducted.

Level three is suitable for the current situation under the four-level security threat alert system, said the president.

In addition, the AoT also requested airline operators to set up their own security committee to provide effective communication channels among airlines in the event of a terrorist attack.

Thai police arrested 48-year-old Atris Hussein at Suvarnabhumi International Airport last Thursday, after receiving a tip-off from Israeli police on possible terrorist attacks on sites in Bangkok popular with Western and Israeli tourists.