KUALA LUMPUR, Malaysia (AP) — Singapore low-cost airline Scoot said Thursday that one of its planes made a U-turn back to the city-state an hour after taking off for Perth due to a bomb threat and then landed safely.

Scoot, a subsidiary of Singapore Airlines Group, said Flight TR16 departed at 4:11 p.m (0811 GMT) from Singapore’s Changi Airport.

“About one hour into the flight, a precautionary decision was made to turn the aircraft back to Singapore due to a bomb threat,” the airline said in a statement. An air force jet was deployed to escort the plane back to the airport, and emergency services were also activated, according to Scoot.

The aircraft landed safely in Singapore at 6:27 p.m. (1027 GMT) and security checks were carried out, the airline said, adding that it could not provide more details because an investigation was ongoing.

“Scoot sincerely apologies for the disruption and inconvenience caused. The safety of our customers and crew is our top priority, and we will continue to provide assistance to our customers,” the airline said.