The US Central Command (Centcom) has confirmed that four of six crew members aboard a US Air Force KC-135 that crashed down in western Iraq have died.
Earlier, a statement shared that the incident was "not due to hostile fire or friendly fire".
The refuelling aircraft has been involved in ongoing US operations against Iran and was one of the two aircraft involved in the incident. The second landed safely.
Centcom said the incident occurred around 14:00 ET on Thursday, and the circumstances surrounding the crash are being investigated.
The identities of the four dead personnel would not be made public for at least 24 hours.
Moreover, Iran's military claimed on state TV that an allied group had targeted the plane with a missile; however, Cenrcom, in their initial statement, noted that the incident occurred in "friendly airspace".
Since the outbreak of the US-Israel war with Iran, seven US soldiers have been confirmed as having been killed in the conflict.
The US military has now lost at least four aircraft during the current war.
Earlier this month, three F-15s were shot down over Kuwait in a mistaken friendly fire incident, and all six crew members were able to safely eject.
