Two flight attendants were stabbed in the attack

Prime Minister John Howard said on Australian radio that evidence pointed to an act by an individual rather than a terror group.

"There is no suggestion this is a terrorist incident... in all probability it is the act of someone who is quite unstable," he said.

"Difficult, traumatic, challenging, horrifying though it will have been for the people involved, it is the first major incident of this kind in about 20 years in Australia so we have to try to keep the thing in perspective," he said.

However Mr Howard admitted that air travellers in the country had changed since the events of 11 September and the Bali bombings.

"We have changed ... People do react now," he said.

Mr Howard's comments come as a 40-year-old man was charged in Melbourne with attempting to hijack the plane, and remanded to appear in court again in August.

David Mark Robinson, who did not enter a plea, faces a possible life sentence if found guilty.

Hero hailed

Thursday's incident, during which the unemployed computer analyst from Melbourne is said to have tried to break into the cockpit of a Qantas Boeing 717, has also prompted airline authorities to launch a full review of airport security.

Suspect Robinson was described as "less than stable"

Two flight attendants were stabbed by wooden sticks and two passengers injured as Mr Robinson reportedly tried to break into the cockpit of Qantas flight QF1737, from Melbourne to Tasmania with 53 passengers and crew on board, before being subdued.

Mr Robinson, who was also said by police to have been armed with an aerosol and lighter, is later said to have told his police interrogators that God spoke to him.

Transport Minister John Anderson later said that Mr Robinson appeared to be "less than stable".

Flight purser Greg Khan, who helped fight off the would-be hijacker despite suffering a severe head wound, was hailed by many as a hero.

"I saw this guy coming towards me, at first I didn't think he was carrying anything ... I thought he may have been going to the toilet," he told Australian reporters.

He said that after realising the man was armed, "I thought I'm not letting him get into the flight deck... so I guess I took him on."

Security alerts

Australia has been on a terrorism alert since being singled out as a target by Osama bin Laden's al-Qaeda network.

On Friday an airport terminal in Sydney was evacuated for 40 minutes by Qantas due to a security breach.

The airline grounded 10 flights, while staff checked the "sterile" area where passengers wait after passing through scanners - but it later played down the alert

A passenger told ABC television that another passenger had broken through the metal detectors and security officials had rushed to find them.