The so-called Islamic State claimed responsibility for two devastating explosions that killed 84 people at a commemoration in Iran marking Qasem Soleimani's assassination by the United States.
The Islamist militant extremist group posted a statement on its affiliate Telegram channels taking responsibility for the attack saying two of its members "activated their explosives vests."
Two bombs exploded in the Iranian city of Kerman on Wednesday and killed scores gathered to commemorate the death of Soleimani, a prominent Iranian general leader killed by a US drone strike in neighboring Iraq in 2020.
The blast was the deadliest attack on Iranian soil in the 45-year history of the Islamic Republic.
Suicide bombers reportedly carried out bombings
Earlier, Iranian state media reported suicide bombers probably carried out the attacks.
The state-run IRNA news agency reported surveillance footage from the route to the commemoration at Kerman's Martyrs Cemetery clearly showed a male suicide bomber detonating explosives.
"The cause of the second blast was most likely the same," IRNA reported, quoting what it called an "informed source."
Soleimani was killed in a US drone attack at Baghdad airport in 2020. He was a high-ranking official in the Islamic Revolutionary Guard Corps (IRGC) and in command of the elite Quds Force, responsible for the Islamic Republic's campaigns abroad.
Iran observed a day of mourning on Thursday, and authorities have also called for mass protests on Friday when the funerals of the victims of the blasts will be held.
Iran vows revenge
Even before "IS" claimed responsibility, Iranian President Ebrahim Raisi condemned the "heinous and inhumane crime," and Iran's top authority, Supreme Leader Ayatollah Khamenei, vowed revenge for the twin bombings.
Earlier, Iran expert at United Against Nuclear Iran, Kasra Aarabi, told DW, "that attack itself certainly has all the hallmarks of ISIS operations in Iran."
He said that would suit the government in Tehran.
"It is likely that the regime will blame ISIS that will enable the [Islamic Revolutionary Guard Corps] IRGC to respond," he said,
"It also domestically has given the regime a pretext to further clamp down on the Iranian people," Aarabi added.
Soleimani was also a staunch enemy of the so-called Islamic State group.
UN Security Council condemns attack
The UN Security Council has condemned the bombings as a "cowardly terrorist attack."
"The members of the Security Council reaffirmed that terrorism in all its forms and manifestations constitutes one of the most serious threats to international peace and security," the UN said in a statement.
It joined the European Union and several countries, including Germany, Saudi Arabia, Jordan, and Iraq, that denounced the blasts.