Singapore's air force and emergency services were activated on Thursday to escort a Scoot flight back to the city-state's Changi Airport after a bomb threat, the budget airline said in a statement.

A "precautionary" decision was made to turn back the Perth-bound flight about an hour into the journey "due to a bomb threat", Scoot said in an emailed statement, without providing details of the threat.

The flight had landed in Singapore as of 6:27 p.m. local time (1027 GMT) where security checks were carried out, the low-cost arm of Singapore Airlines Group said.

"Scoot is assisting the authorities with their investigations. As this is a security matter, we regret that we are unable to provide further details," a spokesperson said, according to media. (Reporting by Kanupriya Kapoor; Editing by Alex Richardson and Sharon Singleton)