A rare daytime rocket attack hit Baghdad's Green Zone on Sunday, security sources said, as Iranian Foreign Minister Mohammad Javad Zarif met top Iraqi officials.
At least two rockets hit outside the US embassy in the high-security zone, they told AFP.
Diplomats based in the neighbourhood said they could hear sirens blaring for around an hour after the attack.
The embassy's C-RAM rocket defence system was not triggered, possibly because the missiles' trajectory meant they would not strike within the compound.
Three dozen rocket attacks have targeted US military and diplomatic installations since October, but usually under cover of darkness.
This time, the attack took place in the searing afternoon heat as Iran's top diplomat held back-to-back meetings with senior Iraqi officials nearby.
Zarif first met his Iraqi counterpart Fuad Hussein early on Sunday, then Prime Minister Mustafa al-Kadhemi, President Barham Saleh, Parliament Speaker Mohammed Al-Halbussi and the head of Iraq's Supreme Judicial Council, Faeq Zeidan.
Zarif is also set to travel north to the Kurdish regional capital of Arbil to meet with officials there.
The trip comes ahead of Kadhemi's own diplomatic flurry: he will visit Iran's regional rival Saudi Arabia on Monday, heading a delegation including his oil, electricity, planning and finance ministers.
The Iraqi officials are to stay in NEOM, an area in the kingdom's northwest currently being developed as a futuristic city.
Kadhemi will meet Crown Prince Mohammed bin Salman, with whom he is known to have warm personal ties.
The delegation will then travel directly to Tehran late Tuesday, where Kadhemi is expected to meet Supreme Leader Ali Khamenei.
Pairing the two trips is an attempt to balance Iraq's complicated ties with both countries, observers say.
Iran has major military and political sway in Baghdad and is the second-largest exporter of consumer goods to Iraq.
But its influence irks both Saudi Arabia and the United States, which is urging Iraq to develop its diplomatic and economic ties to its Gulf neighbours.
Kadhemi rose to the premiership in May after serving as the head of Iraq's National Intelligence Service for nearly four years.
He formed close ties to Tehran, Washington and Riyadh during that time, prompting speculation he could serve as a rare mediator among the capitals.
Kadhemi is also set to visit Washington in the coming weeks, a major milestone in the strategic dialogue currently underway between the US and Iraq.
As part of the dialogue, the Iraqi government has pledged to better protect American installations from rocket attacks while the US vowed to keep drawing down its troop numbers across the country.