The U.S. military on Sunday conducted airstrikes on facilities used by Iran-backed militia groups in the Iraq-Syria border region, CBS News reported.

The targets were facilities Iran-backed militias have used in unmanned aerial vehicle or drone attacks against U.S. personnel and facilities in Iraq, according to a statement from Pentagon spokesperson John Kirby.

"Given the ongoing series of attacks by Iran-backed groups targeting U.S. interests in Iraq, the [U.S.] President directed further military action to disrupt and deter such attacks," Kirby said in the statement, which identified the militant groups Kata'ib Hezbollah and Kata'ib Sayyid al-Shuhada as among those which had used the targeted facilities.

According to Kirby's statement, the U.S. strikes targeted operational and weapons storage facilities at two locations in Syria and one location in Iraq.

A defense official told CBS News that all the targets—command and control and logistics for drones— were hit. There were no indications of civilian casualties.

The U.K.-based monitoring group Syrian Observatory for Human Rights said at least five members of an Iran-backed militant group were killed in the strike in Iraq.

Syrian state TV channel Al Ekhbariya claimed that one child was killed and three people were injured in the airstrike. But Pentagon spokesperson Jessica McNulty told RIA Novosti she had no such information.