ISTANBUL (AP) — A Qatar Airways passenger jet made an emergency landing at Istanbul's main airport shortly after takeoff Thursday following a fire in one of its engines, Turkey's state-run Anadolu Agency reported.

On Twitter, Qatar Airways said the flight "returned to Istanbul and has landed safely. The passengers have disembarked as normal."

It was not immediately clear how many passengers and crew were on board the Istanbul-to-Doha flight.

Anadolu said the emergency landing was ordered after flames came out of the plane's left-side engine. The private Turkish news agency Dogan said the affected plane was an Airbus A330.

Qatar Airways is one of the Mideast's three biggest carriers, alongside the region's biggest carrier, the Dubai-based Emirates Airline, and the Abu-Dhabi based Etihad Airways. The three have increasingly challenged Western airlines in long-haul flights.

Qatar Airways flies out of its hub in the vast new Hamad International Airport in Doha, which is preparing to host the 2022 FIFA World Cup.

Qatar Airways did not immediately respond to queries about the flight from The Associated Press.