Officials did not say what group they believe launched the rocket attack, but Kataib Hezbollah or another Iranian-backed Shia militia group is likely.

The attack came just before 3:30 a.m. local time, according to Col. Myles B. Caggins III, a spokesman for the U.S. military operation in Iraq. He only said the rockets hit the base hosting U.S. and other coalition forces.

The violence is the latest since protests in Iraq reignited last week after a brief lull amid soaring tensions between Washington and Tehran following a U.S. drone strike that killed top Iranian general Qassem Soleimani in Baghdad earlier this month.

Relations with Iraq were fractured after the U.S. launched a drone strike near Baghdad's international airport on Jan. 3 that killed Iranian Gen. Qassem Soleimani.

The attack by at least six rockets came just days after Iran fired ballistic missiles at two bases in Iraq that house U.S. forces, causing no casualties.

There was no immediate claim of responsibility.

The rocket fell inside the Green Zone's Celebrations Square, near the U.S. embassy.

On a range of national security matters, he has cast aside the same warnings that gave his predecessors in both parties pause. Former national security adviser Ben Rhodes likened Trump's foreign policy decisions to that of a "reality show."

Thousands of mourners chanting “America is the Great Satan” marched in a funeral procession Saturday through Baghdad for Iran’s top general and Iraqi militant leaders, who were killed in a U.S. airstrike.

Qassem Soleimani’s death is the latest in a series of escalating incidents traces back to President Donald Trump’s decision to withdraw America from Iran’s nuclear deal with world powers.