One Katyusha rocket fell inside the Green Zone in the Iraqi capital Baghdad on Sunday, Reuters reported, citing a military statement.
No casualties have been reported.
The attack has been the ninth within a week, a Reuters tally based on official statements and security sources, said.
Last month, two rockets hit near the US embassy inside the Green Zone, also causing no casualties.
The Green Zone is often hit by rockets due to the fact that government buildings and foreign embassies are located there, and also because it is not far from the Baghdad International Airport, which is adjacent to a military airfield.