A China Eastern Airlines flight had to return to Sydney after facing a mid-air emergency involving a massive hole blown in its left engine, a spokeswoman for the airline said on Monday (12 June). The Airbus A330 landed safely and no injuries were reported.

Flight MU736 took off from Sydney airport on Sunday night, but the pilot reported problems with the engine an hour into the flight. Passengers also smelt something burning inside the aircraft, so the airbus was immediately turned towards its boarding location, Sydney, where it landed safely.

Images that surfaced on social media show a massive hole in the engine casing, the BBC reported.

Kathy Zhang, general manager of the airlines, said that the flight "encountered an engine problem after take-off".

"The crew observed the abnormal situation of the left engine and decided to return to Sydney airport immediately," Zhang said.

Overnight accommodation for the passengers of the flight was arranged after the emergency landing, she added.

"Today the passengers will be arranged to fly to their destinations on either China Eastern flights or other airlines. The returned aircraft is currently under investigation at Sydney airport," a statement said.

Some passengers said they heard a loud noise coming from the left engine soon after take-off. Crew members reportedly cleared seats near the affected area.

"The cabin crew went out and told us to fasten our seatbelts and tried to calm us down, but we were actually very panicked because we had no idea what was happening," one woman who was on the flight said.

Aviation expert Professor Jason Middleton, from the University of New South Wales Aviation School, described the incident as "very rare".

"Looks like the engine casing or cowling has ripped off, forward of the fan the main initial compressor blade, it's ripped clean off".

"Looks like there's obviously been some preliminary damage in order for that to happen. How that might have happened, I'm not sure.

"It's quite possible if there was some minor damage that they didn't see," he told ABC.