The United States military said on Friday that seven personnel aboard a helicopter in western Iraq were killed in a crash, CNN reported. US Army Brigadier General Jonathan Braga, who heads the operations for the combined task force in Iraq, said there were no survivors.

The helicopter crashed near al Qaim in the western Anbar province of Iraq, near the Syrian border on Thursday. The military said that a second helicopter immediately reported the crash and Iraqi security forces and coalition members secured the area, Reuters reported.

The US Central Command said that the crash did not seem to be the result of “enemy activity”. However, the cause of the accident is not yet known, and an investigation is underway.

The names of the victims have not yet been released. This will be done after their families are notified of their demise, CNN said.

The United States says it has 5,200 troops stationed in Iraq to fight the Islamic State group.