SINGAPORE, Dec 2, 2008 (AFP) - Singapore Airlines said Tuesday it expects to continue twice-daily flights between Singapore and U-Tapao airport in Thailand at least until Friday.

Overseas airlines have turned to the Vietnam-era military airport southeast of Bangkok since late last week while the city's main Suvarnabhumi international and Don Mueang airports are shut down by Thai anti-government protesters.

"Singapore Airlines will continue its twice-daily flights between U-Tapao and Singapore till Friday, with a decision to be taken later in the week about whether the flights will continue into the weekend," the carrier said in a statement.

Singapore Airlines' regional wing, SilkAir, said it would operate 13 extra flights from Tuesday to Sunday between Singapore and the southern Thai resort destination of Phuket.

"By the end of this week, Singapore Airlines and SilkAir will have injected over 15,000 seats into and out of Thailand to help customers stranded by the closure of Suvarnabhumi International Airport," Singapore Airlines said. SilkAir has also mounted additional flights to the northern Thai city of Chiang Mai.

Singapore-based Jetstar Asia said last Friday it would operate its Bangkok service from U-Tapao until further notice.