Two Katyusha rockets fell inside Baghdad's Green Zone, which houses the US Embassy in Iraq, on Wednesday evening, the Iraqi military said.
There were no reports of casualties.
This is the second time this week that the high-security enclave in the Iraqi capital has come under fire. On Saturday, two mortar rounds hit the Green Zone.
The Iraqi military said that one projectile hit inside the zone, while another landed close to the enclave.
The incidents come amid tensions in Iraq between the United States and Iran.
Last week, the US eliminated Qassem Soleimani, the head of the powerful Quds Force of the Iranian Revolutionary Guards Corps (IRGC) in a drone strike near the Baghdad International Airport.
Iran threatened to retaliate for the hit on Soleimani and, on Tuesday night, launched more than a dozen ballistic missiles against US military and coalition forces in Iraq. There were no reports of casualties.
On Wednesday, US President Donald Trump delivered an address to the nation and said that Americans should be "happy" and "grateful" following the killing of Solemaini.
“All of our soldiers are safe,” he said, noting that there were no American casualties in the ballistic missile attacks launched by Iran against US forces in Iraq overnight.
“Iran appears to be standing down," he added.