HONOLULU (AP) _ A Continental Airlines flight from Tokyo to Honolulu hit severe turbulence Wednesday, injuring 18 passengers and four flight attendants.

One passenger was in serious condition with possible rib fractures, but everyone else received bumps, bruises and other minor injuries, said Sarah Anthony, an airline spokeswoman.

Flight 910 landed safely at the Honolulu airport about three hours after hitting turbulence at 33,000 feet, said Marilyn Kali of the state Transportation Department.

The plane was carrying 330 passengers, 15 flight attendants and three pilots, Ms. Anthony said. Most of the injured passengers were sitting in the back of the plane.

In December 1997, one woman was killed and 102 other passengers were injured when a United Airlines Tokyo-to-Honolulu flight hit turbulence and dropped about 100 feet over the Pacific.

Last September, passengers on China Airlines and Japan Airlines flights were injured by turbulence on their way to Honolulu.