Baghdad, Iraq (CNN) -- Three mortar rounds struck harmlessly inside Baghdad's Green Zone on Sunday night during a weekend visit by U.S. Vice President Joe Biden, U.S. and Iraqi officials said.
No damage or injuries were reported from the bombardment, which occurred about 10:30 p.m. Sunday (3:30 p.m. ET).
The district, formally known as the International Zone, houses Iraqi government offices and the U.S. Embassy. But there were no injuries or damage reported from the shelling, Iraqi Interior Ministry and U.S. officials told CNN.
The district was a frequent target of rocket and mortar attacks during the worst of the war that followed the U.S. invasion in 2003. A similar attack struck during a Biden visit in September.
Biden landed in Iraq on Saturday to celebrate the U.S. Independence Day holiday with American troops, the White House said.
He also met with Iraqi political leaders, including Iraqi President Jalal Talabani and Prime Minister Nuri al-Maliki, and with former Prime Minister Ayad Allawi, whose political coalition narrowly won an election in March.
Iraqi political factions are still negotiating who will lead the new government following that vote. Biden told them after their meeting that "you must have all voices represented in this government for it to be successful," and noted later that a country's second election -- not its first -- is "the most important election in a country's history."
"Now there's a new parliament that's been seated, and when the new government is formed, it will mark something absolutely extraordinary -- a peaceful transition of power encompassing all the people of Iraq, maybe for the first time in their history," Biden said during remarks Sunday at Camp Victory, the U.S. base near Baghdad's airport.
And Biden said the withdrawal of U.S. combat troops from Iraq will continue as scheduled, with the pullout expected to be complete by the end of August. But he said 50,000 Americans will remain to train and support Iraqi forces, and the United States will remain engaged with Iraq "diplomatically, politically, economically, culturally (and) scientifically."
CNN's Jomana Karadsheh contributed to this report.