The US military has struck three facilities in Iraq and two anti-ship missiles in Yemen operated by Iranian-backed militias that have continued to instigate attacks on US personnel and ships in the region.

Both the strikes in Iraq and Yemen targeted sites that the US has said are involved in the attacks against US forces in Iraq and Syria and were threatening US military and commercial vessels in the Red Sea.

In a statement on Tuesday, defence secretary Lloyd Austin said the strikes in Iraq were at the direction of President Joe Biden and targeted facilities used by the Iranian-backed Kataib Hezbollah militia group and other Iran-affiliated groups in Iraq.

“These precision strikes are in direct response to a series of escalatory attacks against U.S. and Coalition personnel in Iraq and Syria by Iranian-sponsored militias,” Mr Austin said.

Those strikes hit militia facilities in Jurf al-Sakhar, which is south of Baghdad, al-Qaim and another unnamed site in western Iraq, two US officials said.

Late on Tuesday, US Central Command announced it had also struck two Houthi anti-ship missiles that were aimed into the southern Red Sea and were prepared to launch.

“U.S. forces identified the missiles in Houthi-controlled areas of Yemen and determined that they presented an imminent threat to merchant vessels and the U.S. Navy ships in the region,” Central Command said.

Both fronts — land attacks in Iraq and Syria, and sea attacks originating from Yemen — have seen a significant uptick in launches and counterstrike’s over the last few days.

In Iraq, US strikes on the Kataib Hezbollah sites came hours after the US said militants fired two one-way attack drones at al-Asad Air Base, injuring US service members and damaging infrastructure.

And they followed the militia’s most serious attack this year on the air base, when it launched multiple ballistic missiles on Saturday.

US Central Command said it targeted Kataib Hezbollah headquarters, storage, and training locations for rocket, missile, and one-way attack drone capabilities.

In Tuesday’s drone attacks against al-Asad, US defences were able to intercept the first drone but it crashed on base and the second drone hit the base, US officials said.

Injuries, including traumatic brain injuries and smoke inhalation, were reported to be minor. The officials spoke on the condition of anonymity to provide details that had not been announced publicly.

Tuesday’s strikes on the Houthi missile launch sites in Yemen follow a joint operation on Monday night where the US and UK used warship- and submarine-launched Tomahawk missiles and fighter jets to take out Houthi missile storage sites, drones and launchers.

A coalition of militias calling itself the Islamic Resistance in Iraq has taken credit for a number of the attacks on US forces. Kataib Hezbollah is one of the groups within that umbrella organisation.

Iran has also supplied the Houthis with ballistic missiles.