Severe turbulence jolted a Tokyo-bound Northwest Airlines flight from the Philippines on Friday, injuring 50 passengers and crew members, a company spokesman said.

Four passengers were hospitalized, including one person with a serious neck injury, said Masashi Takahashi, spokesman for Northwest Airlines in Tokyo.

The 46 others, including seven crew members, received light injuries, he said.

Turbulence hit the plane while it was circling off the coast of Chiba, east of Tokyo, about 30 minutes before landing at Tokyo's Narita airport, he said. The plane suddenly descended, sending passengers without their seatbelts fastened lurching from their seats, he said.

The Boeing 747-400 plane was carrying 408 passengers and 14 crew members.

Japanese TV networks showed passengers holding their heads and necks as they left the plane.

"I was so scared, I thought I would die," a passenger who was not named told the TBS television network. "My whole body was lifted into the air."

Fire trucks and ambulances were on the tarmac when the plane landed. One of the passengers was taken away in a wheelchair and another on a stretcher. Some were later wheeled into hospitals on gurneys.

Most of the passengers were believed to have been hurt by hitting their heads or twisting their necks.

A low pressure system off eastern Japan on Friday morning created strong winds and large thunderclouds that can cause air turbulence.