The missiles came down on Sunday in areas near a new US consulate building, according to Kurdish officials. US officials said no Americans were hurt and nor were US facilities hit. Kurdish authorities said only one civilian was hurt and no one killed.
Iranian state media said Iran's Revolutionary Guards Corps carried out the attack against Israeli "strategic centres" in Erbil, suggesting it was revenge for recent Israeli air strikes that killed Iranian military personnel in Syria.
The attack, in which huge blasts shook windows of homes in Erbil after midnight, was a rare publicly declared assault by Tehran against allies of Washington.
The last time Iran fired missiles directly at US facilities was when it struck the Ain Al Asad air base in western Iraq in January 2020, in a retaliation for the US killing of Iranian commander Qassem Soleimani.
Sunday's attack comes as talks to revive the 2015 Iran nuclear deal face the prospect of collapse after a last-minute Russian demand forced world powers to pause negotiations for an undetermined time despite having a largely completed text.
It also comes days after Israel carried out an air raid in Syria which the IRGC said killed two of its members and for which it vowed retaliation.
The IRGC issued a statement about Sunday's attack which was reported by Iranian state media.
"Any repetition of attacks by Israel will be met with a harsh, decisive and destructive response," it said.
The Iraqi Kurdish regional government said the attack only targeted civilian residential areas, not sites belonging to foreign countries, and called on the international community to carry out an investigation.
Iraq's foreign ministry summoned the Iranian ambassador to Baghdad in protest.
A US State Department spokesman called it an "outrageous attack" but said no Americans were hurt and there was no damage to US government facilities in Erbil.
France's foreign ministry said the move threatened efforts to conclude nuclear talks with Iran.
In another sign of derailing regional diplomacy, Iran said on Sunday it was suspending a fifth round of talks due this week in Baghdad with regional rival Saudi Arabia.
US forces stationed in a section of the Erbil International Airport complex have in the past come under fire from rocket and drone attacks that Washington blames on Iran-aligned militia groups, but no such attacks have occurred for several months.
Asked about Sunday's attack, Israel's military said it did not comment on reports in the foreign press and the prime minister's office declined to comment.
Iran has not fired ballistic missiles at US forces since its January 2020 retaliation attack after the US killing earlier that month of Soleimani at Baghdad airport. No US personnel were killed in that attack but many suffered head injuries.
Iran-backed Shi'ite Islamist militias have since Soleimani's death regularly attacked US forces stationed in Iraq and neighbouring Syria. Washington has on occasion retaliated with air strikes.
Iraq has been rocked by chronic instability since the defeat of the Sunni Islamist group Islamic State in 2017 by a loose coalition of Iraqi, US-led and Iran-backed forces.
Since then, Iran-aligned militias have regularly attacked US military and diplomatic sites in Iraq, US and many Iraqi officials say.
Iran denies involvement in those attacks.
