LOS ANGELES -- Investigators found no explosives aboard a Los Angeles-bound Thai Airways flight in which a bomb threat was found scrawled on a bathroom mirror, the FBI said Wednesday.

Airport officials were notified at 7:15 p.m. Tuesday of the alleged threat, FBI spokeswoman Laura Eimiller said.

Flight 794 landed safely at Los Angeles International Airport just before 9 p.m. Tuesday evening and was taken to a remote area of the airport where passengers exited the plane and the search was conducted, Eimiller said.

Investigators conducted a thorough search of the plane and found no evidence to suggest a credible threat to the aircraft existed, she said. All passengers were immediately removed from the plane, interviewed and released, Eimiller said. There were no arrests.

Thai Airways president Piyasvasti Amranand told The Associated Press that the message -- written in English with bad grammar -- warned that a bomb was on the plane.

"This must have caused some nuisance to the passengers," he said by phone from Singapore. "It sounds like it was done by a crazy person."

Thai Airways said in a statement that there were 171 passengers and 18 crew members on board.

The Los Angeles Fire Department said there were 18 fire trucks and fire engines on standby when the plane landed.