Several mortar rounds or rockets on Saturday struck Baghdad's Green Zone, which houses most of Iraq's key institutions and main embassies, security officials and residents said.

"We're not sure whether they're mortar rounds or rockets yet, but several struck the Green Zone tonight," a senior police official told AFP, adding that there were no immediate reports of any injuries.

The incident came hours after seven people were killed when protesters, most of them supporters of cleric Moqtada al-Sadr, tried to force their way through a security cordon to reach the Green Zone.