Islamic State claimed responsibility on Thursday for two explosions in Iran that killed nearly 100 people and wounded scores at a memorial for top commander Qassem Soleimani.
In a statement posted on its affiliate Telegram channels, the militant Sunni Muslim group said two IS members had detonated explosive belts in the crowd that had gathered at the cemetery in the southeastern Iranian city of Kerman on Wednesday.
The memorial was marking the fourth anniversary of the death of Soleimani, who was assassinated in Iraq in 2020 by a U.S. drone.
In Washington, White House spokesman John Kirby told reporters the United States was in no position to doubt Islamic State's claim that it was responsible for Wednesday's attack.
Tehran has vowed revenge for the bloodiest such attack since the 1979 Islamic Revolution. The twin blasts also wounded 284 people, including children.
"A very strong retaliation will be meted out to them by the hands of the soldiers of Soleimani," Iran's First Vice President Mohammad Mokhber told reporters in Kerman.