Int’l Desk:

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

Four of the six crew members aboard a US military aircraft that ​crashed in western Iraq are confirmed to have been killed, the US ‌military said on Friday, as rescue efforts continued for the remaining two.

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

The deaths add to the ​seven US service members who have already been killed as part ⁠of US operations against Iran which began on February 28.

“The circumstances of the incident are ​under investigation. However, the loss of the aircraft was not due to hostile fire ​or friendly fire,” a statement from US Central Command said.

A US official told Reuters that the second aircraft involved in the crash, which landed safely, was also a military refueling aircraft known as the KC-135.

The ​United States has deployed a large number of aircraft into the Middle East to ​take part in operations against Iran and the incident highlights the risk of not just operations, ‌but ⁠of refueling aircraft in the air.

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 allowing aircraft to carry out missions without having to land.

The Islamic ​Resistance in Iraq, an ​umbrella group of ⁠Iran-backed armed factions, claimed responsibility for downing the US military refueling aircraft.

Reuters reported on Tuesday that as many as 150 US ​troops have been wounded in the US-Israeli war on Iran. News ​of the ⁠crash comes the same day two US sailors were injured after the USS Gerald Ford suffered a non-combat-related fire on board.

The first seven US troops were killed when a drone ⁠slammed into ​a US military facility in Port Shuaiba, Kuwait.

President ​Donald Trump and other senior officials have warned the Iran conflict will result in more US military deaths ​as Tehran retaliates against US and Israeli strikes.