The IRGC confirmed early Wednesday morning to Press TV that Ayn al-Asad Air Base was hit after tens of missiles were fired toward the facility, which contains US forces.
"We warn all allied countries of the US that if attacks are launched from bases in their countries on Iran, they will be a target of military retaliation," the IRGC said in a statement obtained by the New York Times' Farnaz Fassihi.
The IRGC warned both the US and regional allies against retaliation following the January 8 strikes in Iraq.
Tehran-based news agency Tasnim reported a total of 35 rockets were fired and, according to VOA News' Carla Babb, "about 35 rounds total hit the base."
Iran's Fars news agency labeled the reported Iranian ballistic missiles fired at the US base as "hard revenge" in a translated social media post.
"Start of Iran's vengeful US retaliation," the news agency said in a since-deleted posting which reportedly showed the launch of several missiles toward the US air base.
“Under missile attack from Iran. These are either cruise missiles or short range ballistic missiles. All over the country," said a senior US military source stationed in Iraq, reported Fox News' Jennifer Griffin.
Missiles were also reportedly fired at the northern Iraqi city of Erbil, which contains a US consulate.
US officials have yet to comment on the number of service members injured or killed in the strike.
"We are aware of the reports of attacks on US facilities in Iraq. The President has been briefed and is monitoring the situation closely and consulting with his national security team," White House Press Secretary Stephanie Grisham said Tuesday.
The IRGC's attack on the US military facilities in Iraq comes hours after Islamic Revolutionary Guard Corps official Maj. Gen. Mortada Qurbani announced his forces were "in a high state of alert to destroy [Europe and the US'] bases in the region and humiliate you."