A number of US personnel were being evaluated for potential head injuries following a ballistic missile attack on Al-Asad Air Base in Iraq, the US Central Command (CENTCOM) said on Sunday.

Multiple ballistic missiles and rockets were launched by Iranian-backed militants on the airbase at 6:30 p.m. local time (1530 GMT/UTC) Saturday, it said.

A loose alliance of groups with Iranian backing calling itself the "Islamic Resistance of Iraq" claimed responsibility for Saturday's attack, as with many of the others recently.

The militants say the intensified strikes are a response for US support of Israel against Hamas.

Most missiles intercepted, possible head injuries

"Most of the missiles were intercepted by the base's air defense systems while others impacted on the base," CENTCOM wrote.

"Damage assessments are ongoing. A number of US personnel are undergoing evaluation for traumatic brain injuries. At least one Iraqi service member was wounded," it said.

The attack, and the use of ballistic missiles not just rockets, marks an escalation compared to other recent attacks of this kind.

Attacks more frequent amid Gaza conflict

Since the Israel-Hamas war began in October, the US military has reported attacks 58 times on its assets in Iraq and another 83 times on facilities or troops in Syria, mainly with rockets or rudimentary drones.

Relatively small contingents of US troops remain in both countries following its operations against the so-called "Islamic State," in a bid to stop the group's resurgence.

The UN Secretary-General’s Special Representative for Iraq that Iraq was "in danger of further being drawn into conflict" amid the fighting in Gaza and again urging "all sides to exercise maximum restraint."

rm/msh (Reuters, AP)