
Antigovernment protesters had stormed the main terminal at Bangkok's international airport yesterday, closing it down.
At Changi's Terminal 1, Thai Airways which had a departure scheduled at 8.10 am was still checkingin people until about 7am.
There was some confusion initially when the airline told customers the flight had been postponed to 11am. It was eventually cancelled.
By noon, many of the airlines operating at Changi Airport had issued media statements to announce that all flights to Bangkok on Wednesday close to 20 would be cancelled.
SIA said in its statement that flights were being cancelled 'due to the deteriorating security situation, and a lack of operational service staff.'
It added that 'efforts will be made to reaccommodate those customers on flights when the security situation stabilises and flights resume.'
SIA said an assessment will be made later about flight operations beyond today, and further advice will be issued on its website, singaporeair.com.
Lowcost carriers Tiger Airways, Jetstar Asia and Thai AirAsia have also cancelled all services to Bangkok, along with Cathay Pacific and Thai Airways.
As to the situation at Bangkok's Suvarnabhumi airport, SIA spokesman Stephen Forshaw said the airline has a group of customers stranded there.
They had arrived in Bangkok from Myanmar on another airline with an onward flight to Singapore, then Jeddah for their Hajj pilgrimage.
Forshaw said: 'Our staff are trying to make them more comfortable, but efforts to allow them to leave on a flight have been unsuccessful'.
Singapore's Ministry of Foreign Affairs said in a media statement that 'the situation in Bangkok remains uncertain' adding that its embassy in Bangkok is closely monitoring the situation.
MFA has advised that Singaporeans who do not have a pressing need to travel to Bangkok, should postpone their trips.