Singapore Airlines' long-haul budget airline subsidiary Scoot has cancelled some 20 flights from Singapore to Shenyang and Qingdao, citing regulatory approval problems.

All flights to both destinations between Nov. 27 this year to Jan. 8 next year are affected as the airline has not been able to obtain all the necessary regulatory approvals for the routes.

Scoot had indicated on the flights selection page of their website and in the passengers' flight itineraries that the flights are subject to regulatory approval.

A Scoot spokesperson contacted said that it is standard practice for airlines to launch destinations and sell fares even before getting regulatory approval.

The airline declined to say how many passengers were affected.

Channel NewsAsia understands however that each Boeing 777-200, of which Scoot's fleet solely comprises of, can seat 402 people.

Affected passengers will have to make alternative travel arrangements.

Scoot tickets for flights from Singapore to Shenyang and Qingdao after Jan. 8 next year are still available for sale.

However, these flights are still subject to regulatory approval.