Four people sustained minor injuries today when a Northwest flight from Japan to Honolulu hit "heavy turbulence."

Northwest Flight 22 landed at Honolulu Airport at 8:10 a.m., and fire and rescue crews were on-scene immediately after getting word of the injuries while the plane was still in the air.

One of the injured was a flight attendant, who sustained head and neck injuries. She was taken to the Queen's Medical Center, where she is in stable condition.

The other three were passengers. Two were transported to Straub Clinic & Hospital, one with a minor back injury and the other with minor neck and arm injuries.

The fourth injured person was treated at the scene for unknown injuries.

Tammy Mori, state Transportation Department spokeswoman, did not have information on where the plane hit turbulence. She did say it appeared to be weather-related.

"It was very heavy turbulence," Mori said. "That is rather unusual."

The flight left from Narita, Japan. Mori did not know how many passengers were aboard.