Two rockets fell on Wednesday inside Baghdad's heavily fortified Green Zone, which houses government buildings and foreign missions, but caused no casualties, the Iraqi military said.
Sirens were sounding inside the Green Zone. Police sources told Reuters at least one of the rockets fell 100 metres (yards) from the US Embassy.
"Two Katyusha rockets fall inside the Green Zone without causing casualties. Details to follow," the military said.
Two loud blasts followed by sirens had been heard in Baghdad, Reuters witnesses said.
There was no immediate claim of responsibility.
Iran launched missiles at US forces in Iraq overnight in retaliation for the killing by the United States last week of Iranian General Qassim Soleimani, raising concern about a wider war in the Middle East.
Iran's missile attack on Wednesday had been intended to kill US personnel at Iraq's al-Asad airbase, the top U.S. military officer said, in remarks that suggested that Tehran was, and perhaps still is, willing to risk major US retaliation.
Army General Mark Milley, the chairman of the Joint Chiefs of Staff, was not ready to say whether Iran was done after its unprecedented attack on two Iraqi bases that host troops from the United States, Canada, Denmark, the United Kingdom and other nations.
Asked if perhaps Iran would see this as an incomplete mission, given the lack of US fatalities, Milley said: "I think it's perhaps too early to tell."
Milley said he and others in the military "fully expect" Shia militia groups in Iraq, backed by Iran, to carry out attacks against U.S. and U.S.-led forces in Iraq and Syria: "That's a very real possibility."
His remarks came hours after President Donald Trump on Wednesday suggested Iran was "standing down" after it fired missiles at U.S. forces in Iraq overnight, as both sides appeared to be looking to defuse a crisis over the U.S. killing of an Iranian general.
This story has been published from a wire agency feed without modifications to the text. Only the headline has been changed.