There are no Americans currently at Balad air base and there were none during the the attack, according to a coalition spokesperson. The base had hosted American trainers, advisers and a company that provides maintenance services for F-16 aircraft, according to an Iraqi defense official who spoke on condition of anonymity in line with regulations.
U.S. Secretary of State Mike Pompeo said in a tweet Sunday that he was“outraged” by the attacks.
“Outraged by reports of another rocket attack on an Iraqi airbase,” he tweeted. “I pray for the speed recovery of the injured and call on the government of Iraq to hold those responsible for these attacks accountable.”
“These continued violations of Iraq's sovereignty by groups not loyal to the Iraqi government must end,” he added.
Sunday's attack wounded an Iraqi air force officer and three enlisted men, Iraqi security officials said. They spoke on condition of anonymity in line with regulations.
Some rockets fell on a restaurant inside the airbase, the officials said.
No group claimed responsibility for the attack.
The base is located some 50 miles (80 kilometers) miles north of Baghdad.
A statement from the Iraqi army's official media office confirmed the attack but said eight rockets hit the base, and that two officers had been wounded. The difference in accounts could no immediately be reconciled.
The U.S. and Iran recently stepped back from escalating tensions following the killing of Gen. Qassem Soleimani, Iran’s top general, in a U.S. airstrike in Baghdad. A senior Iraqi leader of an Iran-backed militia was also killed.
Iran's retaliatory attack for Soleimani's death hit two Iraqi bases, Ain al-Asad and Irbil, where American troops are based.
The limited Iranian strikes appeared to be mainly a show of force, and deescalated tensions that had threatened to turn Iraq into a proxy battlefield.