Shafaq News/ A drone on Saturday evening targeted Ain al-Asad air base, which hosts U.S. and other international forces in western Iraq, anti-US armed groups announced in press release.

The attack is the second in less than 48 hours. It was not clear yet whether the attacks caused casualties or damages.

"Today, we targeted the 'Ain al-Assad' US occupation base in western Iraq with a drone, hitting our targets directly," the statement said.

On Thursday, rockets hit another military base hosting U.S. forces near Baghdad's international airport.

U.S. military forces in Iraq were targeted on Wednesday in two separate drone attacks, with one causing minor injuries to a small number of troops even though the U.S. military intercepted the armed drone.

Last week, Iraqi armed groups aligned with Iran threatened to target U.S. interests with missiles and drones if Washington intervened to support Israel against Hamas in Gaza.

The United States has 2,500 troops in Iraq, and 900 more in neighboring Syria, on a mission to advise and assist local forces in combating Islamic State, which in 2014 seized swaths of territory in both countries.