Several American soldiers were injured in a rocket attack on Ayn Al-Asad Air Base in western Iraq, Reuters reported, citing U.S. officials. No one has claimed responsibility for the attack.

Two explosions were heard in Al-Asad, located west of Baghdad, local media reported late Monday, citing eyewitnesses. According to these reports, US forces attacked the incoming missiles with C-RAM air defenses.

Accounts of casualties came from three anonymous U.S. officials who spoke to Reuters.

According to a report, an Arash-1 missile launcher was discovered near the US base after the bombing. The Arash is an Iranian copy of the Soviet-designed BM-21 Grad multiple launch rocket system.

US President Joe Biden and Vice President Kamala Harris were already in the White House Situation Room when the rocket attack occurred, according to US media. Both the US and Israel were expecting an attack from Iran in retaliation for the assassination of Hamas political leader Ismail Haniyeh in Tehran last week. Israel has not officially claimed responsibility for the strike that killed Haniyeh.

In April, Tehran fired a volley of missiles and drones at Israel following an airstrike on the Iranian consulate in Damascus that killed several high-ranking officials. The Iranian government once again claimed the legal right to retaliate, citing Article 51 of the UN Charter, and reportedly warned Israel of the impending attack via Hungary.

Al-Asad has come under sporadic fire from Iraqi Shiite militias in the past. It was also attacked by Iranian ballistic missiles in January 2020 following the US drone assassination of Islamic Revolutionary Guard Corps (IRGC) General Qassem Soleimani in Baghdad.

Although the US initially said the attack caused only material damage, it was later confirmed that dozens of soldiers at the base suffered “traumatic brain injuries”, or concussions.