The Associated Press overnight cited Iraqi militia officials to say that at least four militants were killed in the US operation along Syria's eastern border - the first strike of which hit a weapons depot inside Syria. Additionally one UK-based Mideast monitoring group said at least seven Iraqi fighters were killed.
"U.S. military forces earlier this evening conducted defensive precision airstrikes against facilities used by Iran-backed militia groups in the Iraq-Syria border region," according to a late Sunday statement. And The Wall Street Journal described on Monday: "The Pentagon said operational and weapons-storage facilities had been struck near the Syria-Iraq border at three locations that it said had been used by the Kata’ib Hezbollah and Kata’ib Sayyid al-Shuhada militia groups."
The escalation has once again set off tensions with Baghdad - not to mention threatening to further complicate Iran nuclear talks in Vienna - at a moment much of Iraq's government is pressuring Western forces to finally be removed from Iraqi soil, given the 'anti-ISIS' mission has long appeared to have been completed. The Iraqi Army issued a blistering statement condemning the "blatant and unacceptable violation of Iraqi sovereignty and national security."
Meanwhile at least one US Congressman noted the glaring lack of war authorization or Congressional approval for the Biden-ordered strikes...
To be expected, Tehran also blasted the airstrikes as creating instability in the region, according to foreign ministry spokesman Saeed Khatibzadeh on Monday. "Definitely, what the US is doing is disrupting the security of the region."
But most importantly in terms setting the stage for potential imminent escalation, a coalition of pro-Iranian Iraqi militias vowed revenge in a statement issued immediately afterward:
"We ... will avenge the blood of our righteous martyrs against the perpetrators of this heinous crime and with God’s help we will make the enemy taste the bitterness of revenge," they said.