A Papua New Guinean airliner sank in waters off the Federated States of Micronesia in the central Pacific on Friday after crash-landing short of a runway, but all passengers and crew on board were confirmed safe.

Air Niugini said in a statement the Boeing 737-800 "landed short" of the runway at Weno airport in Chuuk while landing. A spokesperson of the airline had earlier said the plane was attempting to take off but ended up going off the runway.

[Supplied photo]

It is unclear what caused the incident. The airline said all those on board were able to safely evacuate the aircraft.

Bill Jaynes, one of the passengers on the Air Niugini flight and a journalist with a local Micronesian newspaper, recounted his harrowing experience in a video posted on a Facebook page belonging to local pastor Matthew Colson.

Jaynes said the plane came in "very low. I thought we landed hard, until I looked over and saw a hole in the side of the plane and water was coming in."

Jaynes suffered a minor head injury from the landing but heard other passengers sustained "pretty severe injuries," he said.

Video uploaded to Facebook on an account belonging to Eriko Rekis shows small boats helping passengers to safety, with the almost entirely submerged plane in the background.

Jaynes praised the locals who came to the rescue. "They were awesome."

Air Niugini has deployed an emergency response team to the accident site, and is waiting for further information.