A mortar barrage struck the heavily fortified Green Zone in central Baghdad on Monday, a day after powerful Shiite cleric Muqtada al-Sadr asked his followers to put weapons aside, an Interior Ministry source and a witness said.
"Several mortar rounds landed on the Green Zone around 10 a.m.(0700 GMT)," the source told Xinhua on condition of anonymity.
It was not clear if the attack caused any casualty as the area is under control of U.S. troops, the source said.
A Xinhua correspondent at the scene said that five to six mortar rounds rocked the area and smoke could be seen above.
The attack came a day after Sadr offered a truce following days of fierce clashes between his followers and U.S. backed Iraqi security forces, that have pushed the nation to the brink of even larger bloodshed.
Insurgents frequently targeted the Green Zone by mortars and rockets. The roughly 10 square km area is located on the west bank of the Tigris River which bisects the Iraqi capital