Suspected militants shelled Baghdad's protected Green Zone on Sunday in the first such bombardment in more than three months.
The back-to-back strikes reverberated across the Tigris River to a popular promenade, sending families packing up from fish restaurants and abruptly halting a party at a club.
Violence across Iraq remains sharply down compared with past years, but attacks and bloodshed have edged up in recent weeks and brought worries that it could slow the return of nightlife and commerce to parts of Baghdad.
The US military said the Green Zone was hit by two "indirect fire" rounds - which typically means either rockets or mortars - but there were no casualties or damage reported.
A police official says the rounds were fired from predominantly Shiite eastern Baghdad. The official spoke on condition of anonymity because he was not authorised to speak to media.
The attack came during a light sandstorm, which prevents helicopter patrols and gives militants cover.
The Green Zone was last targeted by rockets or mortars on January 15, leaving one person injured. The attacks are usually blamed on Shiite militias. The area contains the US and British embassies and key Iraqi government offices.
