A barrage of mortar shells landed near the US Embassy in Baghdad just hours after American Vice President Joe Biden arrived in the Iraqi capital on a surprise visit on Tuesday, a security official said.
Biden was unharmed, said a reporter travelling with him.
The security official said four mortars struck near the embassy while an AFP journalist on the scene said at least two shells landed around 100 metres from the sprawling site within the high-security Green Zone.
Fire engines were seen heading to the area but no one from the embassy was available for comment.
A pool reporter travelling with the vice president confirmed that mortars had landed in the Green Zone and that the signal to take cover had been sounded a couple of times, but Biden was "fine."
Biden's visit, his third trip to Iraq this year, was focused on talks with the conflict-hit nation's political leaders and to meet American troops, US officials said.
The vice president told reporters "he has a personal relationship and "has won a measure of trust" from Iraqi leaders, and said he was "here to listen."
Biden has been given a special mission by US President Barack Obama to keep a high-level focus on Iraq ahead of the withdrawal of combat troops from the country by August next year, and all forces by the end of 2011.