Four missing after Australian military helicopter crash

A search is under way to find the crew and their families have been notified.

The aircraft was taking part in Exercise Talisman Sabre, a training operation that involves defence forces from Australia, the United States and other allies. 

The bulk of the exercises are being held in regional Queensland.

Earlier in July, a US Army tank was caught up in a fiery crash near Rockhampton that left six people in hospital.