A ‌US military refuelling aircraft crashed in western Iraq on ‌Thursday in an incident US Central Command said involved ​another aircraft but was not the result of hostile or friendly fire.

The United States has ​sent a large number of aircraft into the ⁠Middle East to take part in ‌operations ‌against ​Iran.

In a statement, US Central Command said it was ⁠carrying out rescue ​efforts after the US ​KC-135 refuelling aeroplane went down. The ‌second aircraft landed safely.

“The ​incident occurred in friendly airspace during ⁠Operation Epic Fury, and ⁠rescue ​efforts are ongoing,” the statement said, using the name of the US operation against Iran.

The statement did not provide details on the fate of the KC-135’s crew.

A US official, speaking on the condition of anonymity, said the other aircraft involved ​in the incident was also a KC-135 and the one that crashed ​had six service members on board.

The KC-135, built by Boeing in the 1950s and ‌early ⁠1960s, has served as the backbone of the US military’s air refueling fleet and is critical to allow aircraft to carry out missions without having to land.

The KC-135 Stratotanker “provides the core aerial refuelling capability for the United States Air Force and has excelled in this role for more than 60 years”, according to a US Air Force webpage. It also provides refuelling for US Navy and Marine aircraft.

Since the US and Israel started carrying out strikes against Iran on February 28, ‌seven US ⁠troops have been killed.

Reuters reported on Tuesday that as many as ‌150 US troops had been wounded in the ​US-Israeli war on Iran. – Reuters and agencies