Four Iraqi soldiers were wounded Sunday in a rocket attack targeting an air base just north of Baghdad where American trainers are present, security officials said.

The Iraqi military said in a statement that eight Katyusha rockets had been fired at the site, about 50 miles north of the capital Baghdad, and that two of the wounded included officers.

Military sources identified the wounded as Iraqi soldiers. They said seven mortar bombs had hit Balad air base's runway.

There was no word of any US casualties among the forces at the site but the incident came just days after another rocket landed nearby.

That missile was launched in the Fadhlan area of the Dujail district in Iraq's northern Salahuddin province, Iraqi police sources said. The origin of the rocket is unknown.

And the two strikes at Balad also came within days of Iran firing ballistic missiles at two other bases in Iraq that also house US forces. There were no casualties.

Joint Base Balad in Iraq. Seven mortar bombs fell on Sunday inside the air base and four Iraqi soldiers were wounded in the attack, two military sources told Reuters

The Iraqi military statement did not say who was behind the attack Sunday and made no mention of heightened tensions between the United States and Iran.

Recent heightened tensions between the U.S. and Iran were sparked last month when a rocket attack killed an American contractor at a base in Iraq.

The US has blamed that attack and others on Iran-backed militias.

The rockets struck Balad air base, which hosts American trainers, advisers and a company that provides maintenance services for F-16 aircraft. Some rockets fell on a restaurant inside the airbase, the officials said.

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.

'There are American experts, trainers and advisers at the base,' said one defense official, who requested anonymity because he was not authorized to speak to media.

Iran's retaliatory attack for Soleimani's death hit Ain al-Asad, pictured

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.