The US strikes appeared limited in scope and narrowly tailored, targeting five weapons storage facilities used by Kataib Hezbollah militants - including facilities used to store weaponry for past attacks on US-led coalition troops, the Pentagon said according to Reuters.

Iraq’s military said in a statement that the US air strikes hit four locations in Iraq.

The US military did not estimate how many people in Iraq may have been killed in the strikes, which officials said were carried out by piloted aircraft.

US Defense Secretary Mark Esper, in a Pentagon statement detailing the strikes, cautioned that the United States was prepared to respond again, if needed.

“We will take any action necessary to protect our forces in Iraq and the region,” Esper said.

Trump had been quick to authorize the US military to respond following Wednesday’s attack in Iraq, in which militants fired dozens of 107 mm Katyusha rockets from a truck, striking Iraq’s Taji military camp north of Baghdad.

Out of the roughly 30 rockets fired, some 18 hit the base. No one has claimed responsibility for the attack.

It was the third time in recent months the US military lashed out against Kataib Hezbollah. It killed more than two dozen militants in December in response to an attack on an Iraqi base that killed a US contractor.

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