Two rockets crashed late Wednesday into the Iraqi capital's Green Zone, the high-security enclave where foreign embassies including the US mission are based, security sources told AFP.
Just before midnight, AFP correspondents in Baghdad heard two loud blasts followed by the wailing security sirens of the Green Zone.
The attack came nearly 24 hours after Tehran launched ballistic missiles at Iraqi bases housing American and other coalition forces, which did not cause casualties.
The strikes were in retaliation for a US drone strike that killed top Iranian general Qasem Soleimani and Iraqi commander Abu Mahdi al-Muhandis last week.
Muhandis had been the deputy head of the Hashed al-Shaabi, a web of armed groups incorporated into the Iraqi state but which also have close ties to Tehran.
The United States had accused Hashed groups of being behind a string of rocket attacks on the US embassy in Baghdad and bases hosting American troops across the country.
On Wednesday, the Hashed's hardline factions vowed they, too, would take revenge for the US raid.
Paramilitary chief Qais al-Khazali -- blacklisted as a "terrorist" by the US -- said Iraq's response to the US "will be no less than the size of the Iranian response."
Harakat al-Nujaba, a hardline Hashed faction, vowed to avenge Muhandis.
"To American soldiers: Do not close your eyes. Revenge for the martyr Muhandis is coming at the hands of Iraqis -- until the last soldier among you leaves," it said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
Drones Strike Iraq Base Housing US-Led Coalition Amid Gaza War Tensions 3 Swedish Citizens Given Death Sentences In Iraq Over Shooting Iraq's Mosul Finds Its Way Back To Life A Decade After It Fell To ISIS Bangladesh Imposes Curfew, Deploys Military As 105 Die In Protests "Jindal Group Executive Showed Porn, Groped Me On Flight": Woman To NDTV Over 300 Indian Students Return Home As 105 Bangladeshis Killed In Protests Joe Biden Is The Best Person To Take On Trump, Says His Campaign Wife Among Two Jailed For Life For Man's Murder In Gurugram: Cops 1,100 Flights Cancelled In US As Microsoft Outage Disrupts Operations Track Latest News Live on NDTV.com and get news updates from India and around the world.