A Qantas jetliner has departed from Los Angeles for Australia after the airline and law enforcement authorities determined a bomb threat was a hoax.

The flight scheduled to leave for Sydney at 10 a.m. finally left at just after 11:30 p.m.

Qantas spokesman Lloyd Quartermaine says the threat that came as a phone call to law enforcement "has been assessed as a hoax." He says as a precaution Qantas worked with U.S. authorities to inspect the aircraft.

The plane's 347 passengers and 20 crew members had to deplane while FBI agents searched the airplane and the luggage for about six hours but found no explosives.

FBI spokeswoman Laura Eimiller says agents are investigating who made the threat.