A drone attack targeted the US Victoria Base in the Iraqi capital Baghdad, security sources said.
No group has claimed responsibility so far.
The base has previously been targeted dozens of times by drone attacks.
The entire region has been on alert since the US and Israel launched an air offensive on Iran on Feb. 28 which has killed more than 1,340 people so far, including then-Supreme Leader Ayatollah Ali Khamenei.
Iran has retaliated with drone and missile strikes targeting Israel as well as Jordan, Iraq and Gulf countries hosting US military assets.
