Baghdad ? Suspected militants shelled Baghdad’s protected Green Zone on Saturday 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 U.S 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 authorized 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 Jan. 15, leaving one person injured. The attacks are usually blamed on Shiite militias. The area contains the U.S. and British embassies and key Iraqi government offices.

West of Baghdad, Iraqi forces launched raids into an industrial zone in Fallujah where authorities fear Sunni insurgents could be seeking to regain footholds in areas they once controlled.

But the offensive into the district of factories and workshops found no clear evidence that al-Qaida in Iraq or its allies had re-established a major presence in Fallujah, said the city’s police chief, Col. Mahmoud al-Issawi.

He said police and military units found only small stockpiles of buried weapons and explosives. No arrests were made during the all-day sweep.

Security forces, however, have sharply stepped up their guard against the possible return of extremist factions to areas that have been relatively calm.

Fallujah, about 40 miles west of Baghdad, was a hub for al-Qaida in Iraq and other insurgent factions before they were mostly driven out by a Sunni tribal uprising and U.S.-led campaigns more than two years ago.