Four of the six crew members aboard the U.S. KC-135 refueling aircraft that went down in western Iraq in the early hours of Friday morning have been confirmed dead, U.S. Central Command officials have said.

Rescue efforts are continuing, and the circumstances of the incident are under investigation, the officials said, although the aircraft’s loss was not due to either hostile or friendly fire.

The identities of the service members are currently being withheld until 24 hours after their next of kin have been informed.

It was earlier reported the plane went down following an “incident” involving another U.S. plane.

The second aircraft subsequently landed safely at the Ben Gurion Airport in Israel, CENTCOM said.

“The incident occurred in friendly airspace during Operation Epic Fury,” it said in its earlier statement, referring to the joint U.S.-Israeli airstrike campaign against Iran that began on February 28.

Citing people familiar with the situation, The Washington Post reported that the second plane was also a KC-135.

Meanwhile, the Islamic Resistance in Iraq, an umbrella group of armed factions backed by Iran, has said that it was responsible for downing the aircraft, confusing the narrative.

The group said in a statement it had shot down the aircraft “in defence of our country’s sovereignty and airspace.”

The latest casualties take the total number of U.S. fatalities from the conflict so far to 11.

Both President Donald Trump and Defense Secretary Pete Hegseth have warned that American deaths in the campaign are inevitable, with the president attracting criticism for describing the prospect in a social media video as, “the way it is,” a choice of words some veterans felt was callous.

But Trump did subsequently observe the dignified transfer of the first six soldiers killed at Dover Air Force Base, Delaware, along with Vice President JD Vance, First Lady Melania Trump, and members of his cabinet.

Hegseth told the CBS show 60 Minutes last weekend: “Things like this don’t happen without casualties. There will be more casualties.

“And no one is – I mean, especially our generation knows what it’s like to see Americans come home in caskets… But that doesn’t weaken us one bit. It stiffens our spine and our resolve to say this is a fight we will finish.”

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