The U.S. airstrike on Sunday

The United States Air Force carries out strikes using F-15E Strike Eagle jets and drones in Iraq and Syria in retaliation for the death of an American civil contractor in a rocket attack on K-1 Air Base in Kirkuk Governorate. The strikes were targeted at the Iranian-backed Kata'ib Hezbollah militia group. A spokesman for Kata'ib Hezbollah, says 19 of its fighters were killed and 35 injured in the American strikes, while vowing to respond.

Trump aides call U.S. strikes on Iraq and Syria 'successful,' warn of potential further action

Sources:  France 24  Reuters  The Washington Post