A US Marine Corps aircraft crashed on a north Australian island on Sunday, killing three Marines and injuring 20 during a multination training exercise, officials said.

Three had been confirmed dead on Melville Island and five of the 23 on board were flown in serious condition 80 km to the mainland city of Darwin for hospital treatment after the Bell Boeing V-22 Osprey tiltrotor aircraft crashed around 9.30 am local time, a statement from the Marines said.