Drones and rockets targeted two military bases housing US forces in Iraq on Thursday, the latest in a series of attacks after Iraqi militants warned Washington against supporting Israel against Hamas in Gaza.

Rockets and drones were fired at Ain al-Asad air base, which hosts US and other international forces in western Iraq, and multiple blasts were heard inside the base, two security sources said.

The Iraqi military said it closed the area around the base and started a search operation. It was not clear yet whether the attacks caused casualties or damage, said the sources.

Rockets hit another military base hosting US forces near Baghdad's international airport, Iraqi police said on Thursday, without providing further details.

A US official, speaking on the condition of anonymity, said two rockets had been fired at US forces at the airport. One was intercepted and the other hit an empty storage facility and there were no casualties, the official added.

The latest attacks take to four in the past 24 hours targeting Iraqi military bases that hosts US forces in Iraq.

Last week, Iraqi armed groups aligned with Iran threatened to target US interests with missiles and drones if Washington intervened to support Israel against Hamas in Gaza following the deadly incursions by Hamas militants that killed 1,400 people.

US 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 US military managed to intercept the armed drone.

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 swathes of territory in both countries.

Ain al-Asad air base is located in the western Anbar province.

Report by Reuters