ISIS Claims Responsibility for Truck Bomb Attack That Killed at Least 60 in Iraq Many of the dead are believed to be Iranian pilgrims.

 -- A truck bomb left dozens dead and injured in an attack apparently targeted at Shia religious pilgrims on Thursday in the Iraqi city of Hilla -- 60 miles south of Baghdad.

The exact death toll is uncertain. Iraqi police have said that 60 people have died and 25 are wounded, while the head of the Babylon provincial security committee told ABC News earlier that more than 70 were killed and 20 wounded. The White House said "initial reports indicate at least 80 people" are dead.

Falah al-Radhi, the provincial security chief, told ABC News that many of the dead were Iranian Shia pilgrims who were taking part in an Arba'een pilgrimage -- an annual religious event in the holy city of Karbala.

Iraqi and Afghan citizens were also among the wounded and dead, according to police officials.

ISIS, which is associated loosely with Sunni Islam, took credit for the attack in a short statement made through its Amaq News Agency.

Al-Radhi said that a fuel tanker was used to attack a gas station near the city of Hilla. Police officials said the blast was so big that it destroyed most of the gas station and damaged buildings 150 yards away from the epicenter.

The U.S. State Department said that initial reports stated that some of the victims were sitting together and enjoying a meal when the attack happened.

The White House condemned the attack, saying: "The United States extends its deepest sympathies to the families of the victims, as well as to all of Iraq, for this senseless violence, which was clearly intended to stoke sectarian tensions."

The State Department echoed the White House, saying it condemned the attack "in the strongest possible terms." The department added: "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."

Arba’een commemorates the martyrdom of Imam Hussain, the prophet Muhammad’s grandson. Traditionally, the event sees Shia observers march from Baghdad to Karbala on foot. According to Euronews, tight security measures had been enacted for this year’s events, with soldiers, ambulances and armored cars escorting pilgrims along the route.

The attack is the latest in a string of deadly bombings across Iraq this year perpetrated by ISIS and aimed at followers of Shia Islam.

In July, an attack on a commercial district reportedly killed more than 300. Car bombings in May reportedly left around 100 dead. In March, an attacking using a fuel tanker truck -- as is the case in today's attack -- left at least 47 dead in Hilla, according to BBC News. And in February, twin suicide bombings killed 70 people in a Shia-dominated district of Baghdad, the Guardian newspaper reported.

Faiq reported from Baghdad, Iraq, while Blake reported from New York. ABC News’ Lena Masri, John Parkinson and Kirit Radia contributed to this report.