Melbourne:Australian Transport safety watchdog is probing the sudden altitude plunge of a Qantas plane that injured at least 40 passengers and crew, 15 seriously, while it was en route from Singapore to Perth

Flight 72,which was carrying 303 passengers, had to make an emergency landing at Learmonth airport, near Perth after it suddenly lost altitude on Tuesday.

Fifteen passengers and crew, who were mainly at the rear of the aircraft, had suffered serious injuries, including broken bones and severe lacerations after the incident, according to media reports here.

A Qantas spokesman said it was too early to speculate on the cause of the plunge, but the West Australian Police Commissioner, Karl OCallaghan, said he understood the incident was caused by "some sort of systems failure".

Ben Cave, of Perth, who was among 280 of the passengers to be flown to Perth, said he had not been wearing a seat belt and had slammed into the cabin roof when the plane plummeted.

He said for a few seconds he had feared for his life and "saw a bit of a flash before me". "We had a major fall and another fall shortly after," Cave said adding "I hit the ceiling but I was okay, I only got a few bruises and strains. I just remember seeing that the plane was a mess."

Source : DNA