STORY: Debris and burned out vehicles litter the ground in the Iraqi city of Hilla, where the U.S. military said it carried out air strikes against Iran-aligned militants on Monday.

At least one serviceman was killed and 18 other people were wounded.

Iraq’s government condemned the strikes as a “clear hostile act”.

Two Iraqi security sources said the strikes targeted the headquarters of Iraqi armed group Kataib Hezbollah in Babil Province south of Baghdad.

Iraq’s central government has limited control over some Iran-backed factions.

Mourners later carried the coffin of the fighter during the funeral in Baghdad.

One of the attendees, Sheikh Fadel Al-Ghazi, said the air strikes were a serious crime and a blatant violation of the sovereignty of the Iraqi state.

The U.S. strikes were retaliation for an earlier drone attack on an Erbil air base in Iraq that left a U.S. soldier in a critical condition and wounded two others.

The back-and-forth clash was just the latest example of how the Israel-Hamas war is rippling across the Middle East.

The U.S. is Israel’s closest ally and the conflict has turned U.S. troops at bases in Iraq and Syria into targets.

There are 900 U.S. troops in Syria and 2,500 in Iraq, to help advise local forces preventing the resurgence of Islamic State, or ISIS.

The U.S. military has already come under attack at least 100 times in Iraq and Syria since the Israel-Hamas war began in October.

The latest unrest comes less than a week after U.S. Secretary of Defense Lloyd Austin returned from a trip to the Middle East, focused on containing efforts by Iran-aligned groups to broaden of the Israel-Hamas war.