WASHINGTON     -    US President Joe Biden said Thursday that US air and artillery strikes that killed four militants in eastern Syria were ordered to protect US forces from attacks by Iran-backed militia.

“I directed the August 23 strikes in order to protect and defend the safety of our personnel . . . and to deter the Islamic Republic of Iran and Iran-backed militia groups from conducting or supporting further at­tacks on United States personnel and facilities,” Biden said in a statement informing Congress of the action.

He said the US strikes, the heavi­est action by American forces in the region in many months, responded to a series of rocket attacks on the facilities of US and partner troops in the area, including two on the al-Tanf Garrison and the Mission Support Site Green Village on August 15.

Biden said the retaliatory strikes, which involved Apache attack heli­copters, AC-130 gunships and M777 artillery, targeted a facility used by the attackers for logistics and am­munition storage. The first US strikes took place on Tuesday. But after the militants launched a new barrage on US positions on Wednesday, a heftier force of American aircraft flew in to push back. In total four militants were killed and seven rocket launch­ers destroyed, the US Central Com­mand, which oversees Middle East operations, said in a statement