ISIS claims responsibility for Iran's bloodiest attack since the 1979 revolution

The devastating twin bombs near Qasem Soleimani's grave in southern Iran were claimed by ISIS.

The bombs on Wednesday killed 84 and injured 284, according to IRNA, making it Iran's bloodiest strike since 1979.

Al-Furqan, an ISIS media branch, said on Thursday that two suicide bombers detonated their vests as Shiite mourners gathered for the fourth anniversary of Soleimani's assassination near his grave in Kerman.

ISIS has attacked Iranian shrines and religious places because it deems Shia Islam heretical.

No further documentation was provided, and their version of the bombings differed from Iranian media. ISIS recorded many more deaths than Iranian government.

Iranian interior ministry said the two bombings happened quickly, with the second, deadlier blast happening as people raced to help the wounded.

IRINN, another state media station, reported that a suitcase bomb in a car was remotely detonated, not a suicide bomber.

Iran's President Ebhrahim Raisi canceled a trip to Turkey on Thursday to mourn.