A suicide bombing claimed by Islamic State (IS) militants has killed at least 80 people, most of them Iranian pilgrims, some 100 kilometers south of Baghdad, according to Iraqi officials.
The truck bomb tore through a gas station with an adjacent restaurant where buses packed with pilgrims were parked as the believers returned from the commemoration of Arbain in Karbala on November 24.
"There are at least 70 dead, fewer than 10 are Iraqis, the rest are Iranians," Falah al-Radhi, head of the security committee for the Babylon provincial council, was quoted as saying by AFP.
Citing police and medical sources, Reuters said the death toll had reached around 100 later on November 24.
Dozens of others were wounded in the attack.
IS militants claimed responsibility for the attack in an online statement, saying one of their Iraqi fighters had carried out the bombing.
The group, which considers Shi'a apostates, warned that "what awaits them in the immediate future, Allah permitting, is more sorrowful and bitter."
Iran's semiofficial ISNA news agency quoted an "informed source" in Baghdad as saying that 50 Iranians were killed in the attack near Hilla.
The pilgrims were on their way back to Iran from the Shi'ite holy city of Karbala where they had commemorated Arbain, the 40th day of mourning for the killing of Imam Hussein, a grandson of the Prophet Muhammad.
The United States condemned the "outrageous attack," while expressing its condolences to the victims’ families and friends.
"These murders are yet another example of Daesh's contempt for human life and its efforts to sow discord and division among the Iraqi people," U.S. State Department John Kirby said in a statement, using an alternative name for the extremist group.
Iran's Foreign Ministry said it "strongly" condemned the attack.
Foreign Ministry spokesman Bahram Ghasemi said the "brutal and inhuman" attack would not affect "the joint relentless fight by Iran and Iraq against terrorism."
The November 24 attack came a day after a series of small-scale bomb attacks in and near Baghdad that left 31 people dead and more than 100 wounded.
Government troops in the north of the country, meanwhile, drove IS forces out of three more neighborhoods in Mosul, the site of a U.S.-backed military push to reclaim the city that was launched six weeks ago.
With reporting by AFP, Reuters, the BBC, ISNA, IRNA, AP, and The New York Times