Iraqi security officials said that the rockets target the area at 7:30 am (0430 GMT), wounding a woman and her three children, AFP reported. No causalities have yet been reported.
Panetta was visiting the US military’s Camp Victory on Baghdad’s western outskirts at the time of the attack.
The Pentagon chief is due to meet President Jalal Talabani and Prime Minister Nouri al-Maliki inside the heavily-fortified Green Zone, which houses the US Embassy, other foreign missions and Iraqi government offices, later on Monday.
Panetta, a former CIA director who took over the charge from Robert Gates on July 1, is the latest US official to visit Iraq to pressure Iraqi leaders to allow thousands of US troops stay in the country beyond the 2011 deadline.
There are currently about 50,000 US troops stationed in Iraq, who are due to leave Iraq by the end of this year in line with the Status of Forces Agreement (SOFA) signed between US and Iraq in 2008.