Four members of Iraq's military were wounded in a rocket attack on a base north of Baghdad, Iraq's military said Sunday.
The attack on was on Balad air base, about 80 kilometers north of Baghdad. U.S. defense officials confirmed to VOA were no U.S. troops on the base.
Although there were no American casualties, Secretary of State Mike Pompeo tweeted Sunday that he is "outraged" by the attack and calls on the Iraqi government to hold whoever was behind it responsible.
Eight Katyusha rockets were fired at the base, just days after Iran fired ballistic missiles at two bases in Iraq which also house American military.
There was no immediate claim of responsibility for Sunday's attack.
The attack comes amid increasing tensions between Iran and the United States after a U.S. drone strike killed Gen. Qassem Soleimani, Iran's top general, earlier this month.
The U.S. announced new sanctions on Iranian companies and eight senior officials, in response to the Iranian missile attacks against bases housing U.S. forces in Iraq. U.S. officials have insisted Soleimani was plotting attacks on U.S. facilities.
VOA's Carla Babb contributed to this report.