On 28 June 2021, President Biden directed airstrikes against Iran-backed militia groups close to the Syria-Iraq border. F-15E and F-16 aircraft were used to launch the attack in what the U.S. described as a retaliatory attack against U.S. facilities and personnel in Iraq by militia groups. Two operational and weapons storage facilities were targeted in Syria, the U.S. military revealed in a statement. Despite the U.S. not disclosing the information regarding the casualties in the attack, the SOHR stated that at least nine Iran-backed Iraqi militia fighters died, leaving many others injured. Iraqi militia groups aligned with Iran in a statement named four members of the Kataib Sayyed al-Shuhada faction they said were killed in the attack on the Syria-Iraq border.