At least 10 rockets struck a US airbase in Iraq late Tuesday, the latest in a series of attacks on American forces in the country.
The rockets were fired at Ain al-Asad air base, in western Anbar province, from a launcher located about five miles from the base, sources said.
The base hosts US and coalition troops alongside Iraqi forces, but no casualties have been reported so far.
The attack comes ahead of Pope Francis's visit to Iraq, which is due to begin on Friday and will mark the first time a pope has been to the country.
Ain al-Asad air base is the second largest airbase established during US occupation of Iraq between 2003 and 2011.
It came under attack by Iran last year following a drone strike ordered by President Trump which killed General Qasem Soleimani.
Iran fired 15 Fateh-313 missiles at two US bases in Iraq during that attack: Ain al-Asad and another facility in Erbil.
Ten of the rockets hit the US airbase and one landed at the Erbil facility while four failed in flight, American military sources said at the time.
No US troops were killed in that attack but 109 were later diagnosed with brain injuries from the force of the explosions.
It is not yet clear who was behind Tuesday's rocket attack. The base has also come under attack from ISIS militant in the past.
The rocket strike comes just days after Joe Biden authorized his administration's first airstrike on an Iran-backed Shia militia compound in neighbouring Syria.
Seven 500lbs bombs were dropped on a compound used by two Iranian-backed Shia militia groups, killing an estimated 22 people.
Military sources said the airstrike was intended to 'draw a line' after a series of attacks on US positions in Iraq.
On February 15, a volley of rockets fell within the grounds of Erbil's international airport and in residential parts of the city, killing a contractor while wounding several US personnel and Iraqi civilians.
The Green Zone in Baghdad, where the American embassy is located, has been a regular target for mortar and rocket fire.
The compound in Syria had been used by militants to smuggle weapons across the border and into Iraq, the US said.