Civil aviation chiefs have asked Dragonair for a full report into why one of their aircraft had to make an emergency return to Beijing airport just 20 minutes after take-off.

Initial investigations suggest an engine problem caused smoke to fill the cabin of one of the airline's Airbus A-330s flying to Hong Kong on Sunday afternoon, forcing it to return to the capital.

Flight KA991 took off from Beijing at 1.47pm with 304 passengers and crew on board and within

minutes of take-off the pilot announced they were experiencing engine problems.

Passengers said sparks came from the left engine, causing some to become so afraid that they vomited.

As fumes filled the cabin the oxygen masks were deployed. Some passengers reported an acrid, charred smell and the sound of minor explosions.

To the delight and applause of passengers the aircraft landed safely at 3pm.

A Dragonair spokesman apologized to passengers and said they had arranged alternative flights back to Hong Kong.

The deployment of oxygen masks was described as "precautionary."

There have been a number of similar incidents over the past two years.

The most recent incident in July last year involved a Hong Kong Airlines flight bound for the city from Korea that was forced to make an emergency landing.

A month earlier, Dragonair flight KA720 bound for Changsha, Hunan province, with 71 passengers and crew on board, had to return to Hong Kong.

It was forced to do so after experiencing mechanical problems 30 minutes after take-off.