PERTH // A Qantas plane hit turbulence and suddenly lost altitude over Malaysia, throwing terrified passengers around the cabin and leaving seven people injured, the airline said. The Airbus A330 with 219 passengers and crew aboard was flying from Hong Kong to Perth overnight when it struck "severe turbulence" over Malaysian Borneo, Qantas said in a statement. Passengers later described the panic and confusion in the darkened cabin as passengers not wearing seat belts were hurled from their seats. "It appeared like we'd just dropped out of a 30-storey building," uninjured passenger Keith Huxtable said. "It was dark ... people screamed." Passenger Michelle Knight, also not hurt, said the crew told her the plane had plunged 30 metres. Six passengers and a crew member were treated on board for minor injuries, Qantas corporate affairs manager David Epstein said. The captain reported minor damage inside the cabin, Mr Epstein told Fairfax Radio. Australian government safety officials were investigating the incident. A computer malfunction on a Qantas A330 flying from Singapore to Perth in October caused the jet to nose-dive twice, leaving 12 passengers and crew seriously injured. The Australian airline underwent a safety review last year after a series of problems, including an oxygen tank explosion on a Boeing 747-400 that ripped a hole in the jet's fuselage last July, forcing it to make an emergency landing in the Philippines. No one was injured.