Three Katyusha rockets landed in Baghdad Airport, damaging four vehicles, the Iraqi military said.The attack took place in the evening when the rockets were fired from Abu Gharib area, west of Baghdad's city center, and landed in the airport, the media office of the Iraqi Joint Operations Command (JOC) said in a statement on Sunday, Xinhua news agency reported.One of the rockets struck a car park in the airport and caused damage to four civilian cars, the JOC said.No group has so far claimed responsibility for the rocket attack. Baghdad Airport and the Iraqi military bases housing US troops across Iraq, as well as the US embassy in the Green Zone, have been frequently targeted by mortar and rocket attacks.More than 5,000 US troops have been deployed in Iraq to support the Iraqi forces in the battles against the Islamic State militants, mainly providing training and advising to the Iraqi forces.