Islamic State (IS) 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, Reuters reported.

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 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.

Tehran has vowed revenge for the bloodiest such attack since the 1979 Islamic Revolution. The twin blasts also wounded 284 people, including children.

An anonymous source told the Iranian state-run IRNA news agency that the first explosion at the Kerman cemetery "was the result of an operation by a suicide bomber."

The reason for the second explosion is also, most likely, the result of an attack by suicide bombers.

The first suicide bomber was a man.