Washington, Jan 9 (IANS): US Secretary of Defence Mark Esper has said Iran launched 16 short-range ballistic missiles from three locations within Iran in Wednesday's attack on the US air bases in Iraq.

Esper, with Chairman of the US Joint Chiefs of Staff Mark Milley aside, told reporters on Wednesday that out of 16 missiles, 11 hit the Ayn al-Asad air base and at least one landed at a base near Erbil, adding that the missiles damaged tents, taxiways, parking lots and a helicopter, Xinhua reported.

Milley said Iran's missiles were aimed at facilities and personnel at the two bases in Iraq.

"I believe, based on what I saw and what I know, that they were intended to cause structural damage, destroy vehicles and aircraft, and to kill personnel," he noted, pointing out that defensive techniques of US forces helped to keep the damage at a limited level.

In his address to the nation earlier on Wednesday, US President Donald Trump attributed the absence of casualties to the precaution measures, dispersal of forces, and effective early warning system.

The Pentagon on Tuesday confirmed Iran's launching of more than a dozen ballistic missiles against at least two military bases housing the US and coalition forces in Iraq.

Iran's Islamic Revolution Guard Corps claimed responsibility for the missile attacks, saying that they were meant to retaliate against the US killing of General Qassem Soleimani.