A flight that took off from Harbin, capital of Heilongjiang province, was forced to make a return voyage and an emergency landing after the outer cover of an engine of the aircraft dropped mid-flight, China News Service reported.

The Guangzhou-bound China Southern Airlines flight, which took off the from Harbin Taiping International Airport at 8:29 am on Monday, made an emergency landing at the airport two hours later, the report quoted airline employees as saying.

One passenger on the flight said that a loud noise was heard after the plane took off and passengers sitting near the emergency exit saw the outer cover of one engine become detached from the aircraft and then notified the cabin crew.

Most passengers on the flight were calm during the incident, according to passengers.

The aircraft used on the flight was an Airbus A320, the report said.