WASHINGTON: Five American service members were killed when a helicopter crashed into the Mediterranean during a training exercise, the US military said on Sunday.

Military officials did not specify where the helicopter was flying from, but the United States has deployed a carrier strike group to the Mediterranean as part of efforts to prevent the Gaza unrest from spiraling into a regional crisis.

`During a routine air refuelingmission as part of military training, a US military aircraft carrying five service members suffered a mishap and crashed into the Mediterranean Sea. All five of the service members onboard the aircraft were killed,` the US European Command (EUCOM) said in a statement.

President Joe Biden, in a statement from the White House, paid tribute to the victims, who died on a weelcend when Americans were honoring military veterans.

`Our service members puttheir lives on the line for our country every day,` Biden said. `They willingly take risks to keep the American people safe and secure.

And their daily bravery and selflessness is an enduring testament to what is best in our nation.

Defence Secretary Lloyd Austin also offered his condolences in a statement that identified the crashed aircraft as a helicopter.

While EUCOM initially said the crash occurred on Nov 10, Austin said the helicopter went down on Saturday morning.There have been multiple other crashes of US military aircraft in recent years, including an F-35 stealth warplane that went down in September, with the pilot able to eject.

In March, two US Army helicopters crashed during a training mission in Kentucky, killing all nine soldiers on board.

And four US Marines were killed during Nato exercises in Norway last year when their V-22B Osprey aircraft went down.-AFP