BAGHDAD - 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 US 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 US 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 US over Soleimani's death.

Saturday attack also came after Iraqi protesters on Tuesday stormed the US 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.