ERBIL, Kurdistan Region of Iraq - US Central Command (CENTCOM) announced Friday that four US military personnel were killed after a refueling aircraft crashed over Iraq the day prior, insisting that "the loss of the aircraft was not due to hostile fire."

"Four of six crew members on board the aircraft have been confirmed deceased as rescue efforts continue," the command said in a statement.

Two aircraft were involved in the Thursday incident according to the US military, with one having crashed while another was able to land at a regional airport, with images having circulated of a damaged KC-135 in Tel Aviv.

"The circumstances of the incident are under investigation. However, the loss of the aircraft was not due to hostile fire or friendly fire," CENTCOM noted.

Despite the denial, the Islamic Resistance in Iraq, an umbrella group comprising numerous pro-Iran factions, claimed responsibility for downing the plane.

"In defense of our country's sovereignty and its airspace ... the Islamic Resistance in Iraq shot down a KC-135 aircraft belonging to the American occupation in western Iraq, using appropriate weaponry," the group said in a statement.

A second statement claimed that a second KC-135 was later hit but "managed to escape" and land at an "enemy" airport.

The incident brings the total number of confirmed US military casualties since the commencement of its military campaign against Iran in mid-February to 11.

US military bases across the Middle East have repeatedly come under attack by Iran and Iran-aligned forces, with the American presence at Erbil International Airport having been incessantly targeted since the beginning of hostilities.

Kurdistan Region leaders have repeatedly urged Baghdad to rein in the activities of pro-Iran groups, with President Masoud Barzani having warned that "patience has its limits" amid the nightly bombardment of the Region.

On Wednesday, Iraqi Prime Minister Mohammed Shia' al-Sudani held a phone call with Iranian President Masoud Pezeshkian, telling him that Iranian strikes on Iraqi territory are "unacceptable" and Iraq will not be used as a "launching pad" for attacks on its neighbor.