Protesters set fire to a guard room outside the U.S. embassy in Baghdad, Iraq on Dec. 31, 2019. Hundreds of demonstrators, participating in mourning for the Hashd Shaabi members killed by U.S. attack in Iraq, stormed the U.S. embassy in Baghdad's Green Zone on Tuesday, a security official said. Many of the protesters, wearing Hashd Shaabi's military uniforms, rallied outside the embassy chanting slogans condemning airstrikes by the U.S. forces against Hashd Shaabi bases in Iraq. Photo:Xinhua

A Katyusha rocket on Saturday landed on the heavily fortified Green Zone in central Baghdad, but no reports about casualties, an Interior Ministry official said.

The incident took place in the evening when a Katyusha rocket hit the zone, which houses some of the main offices of the Iraqi government and the U.S. embassy, the official told Xinhua on condition of anonymity.

The heavily fortified Green Zone has been frequently targeted by mortar and rocket attacks. The roughly 10 square km zone is located on the west bank of the Tigris River, which bisects the Iraqi capital.

The attack occurred after a U.S. drone attack ordered by President Donald Trump killed Qassem Soleimani, commander of the Quds Force of Iran's Islamic Revolution Guards Corps, and Abu Mahdi al-Muhandis, deputy chief of Iraq's paramilitary Hashd Shaabi forces.

The attack took place on the Baghdad international airport's road early on Friday.

Iran's Supreme Leader Ayatollah Ali Khamenei and President Hassan Rouhani have vowed to retaliate against the U.S. over Soleimani's death.

Saturday attack also came after Iraqi protesters on Tuesday stormed the U.S. embassy compound in Baghdad to protest the American air raids conducted on Dec. 29 against five bases of Iran-backed militias in Iraq and Syria, claiming the lives of 25 militants.