At least 10 rockets landed on Wednesday at Iraq's Ain al-Asad air base that hosts United States, coalition and Iraqi forces, the Iraqi military said.
It was the second rocket attack in Iraq this month and came two days before Pope Francis is due to visit the country.
The attack caused no significant losses, Iraqi's military said without going into further detail.
A Baghdad Operations Command official told Reuters earlier that about 13 rockets were launched from a location about 8 km (5 miles) from the base, which is in western Anbar province.
Another Iraqi security source and a government official who spoke on condition of anonymity said the rockets were launched from the Baiader area, west of Baghdadi city.
The Pope will visit Iraq from March 5-8 despite deteriorating security in some parts of the country.
On Feb. 16 a rocket attack on US-led forces in northern Iraq killed a civilian contractor and injured a US service member.
US Army Colonel Wayne Marotto, spokesman for the US-led coalition, said on Twitter that the rockets targeted the base at 7:30 am Iraq time on Wednesday.