Survivors of a military helicopter crash in Australia have been transferred to hospital following an incident involving US marines on an island off the coast of Darwin on Sunday, according to media reports.

At least three personnel have been retrieved from the crash site on Melville Island around 60 kilometers (37 miles) from Darwin with one in critical condition, while the other two are stable, ABC News reported. The Australian newspaper said it understood most or all of those on the aircraft had survived, according to a separate report.

The V-22 Osprey went down while performing drills which involved military personnel from the US, Australia, Indonesia, the Philippines and Timor-Leste, Sky News Australia reported.

“This is a difficult incident, we are responding fully and our priority is on providing every assistance possible,” Australian Prime Minister Anthony Albanese said to reporters Sunday. “We do follow protocols at a time like this and the Australian Defence Force are cooperating with our friends in the US Defense Force.”

An Australian Defence spokesperson confirmed an aircraft incident occurred mid-morning during Exercise Predator’s Run 2023, without providing details.

“Initial reports suggest the incident involves United States defence personnel and that Australian Defence Force members were not involved,” the spokesperson said in an email. “At this critical early stage, our focus is on the incident response and ensuring the safety of those involved.”

A US Defense Department spokesperson said: “We are aware of the public reporting on this, but we do not have anything we can provide at this time.”

The helicopter crash marks the second in Australia during training drills in less than two months. In late July, an Australian army helicopter crashed off the coast of Queensland in northeastern Australia, killing four Australian military personnel on board.

Prior incidents with the V-22 Osprey, which can tilt its rotors, included a crash in 2000 that killed 19 marines.

(Updates throughout.)