Two explosions have killed more than 100 people and wounded scores at a ceremony in Iran to commemorate top commander Qassem Soleimani who was killed by a US drone in 2020, Iranian officials say, blaming unspecified "terrorists".
Iranian state television reported a first and then a second blast during a crowded anniversary event at the cemetery where Soleimani is buried in the southeastern city of Kerman.
No one claimed responsibility for the blasts.
Iranian President Ebrahim Raisi condemned the "heinous and inhumane crime" and Iran's top authority Supreme Leader Ayatollah Khamenei vowed revenge for the bloody twin bombings.
"Cruel criminals... must know that they will be strongly dealt with from now on and... undoubtedly there will be a harsh response," Khamenei said in a statement, according to state media.
Several countries, including Russia and Turkey, condemned the attacks, and the United Nations Secretary-General called for those responsible to be held accountable.
Iranian Health Minister Bahram Eynollahi told state TV the death toll was at 95, down from 103, and said 211 others were injured, making it the deadliest attack in the history of the Islamic Republic, which has faced similar incidents in the past from various militant groups including the Islamic State.
Iran has in the past blamed Israel for attacks on individual people or places within its borders - claims which Israel has neither confirmed nor denied - but there was no indication of any involvement of a foreign state in the cemetery explosions.
An unnamed official told state news agency IRNA that "two explosive devices planted along the road leading to Kerman's Martyrs' Cemetery were detonated remotely by terrorists".
Videos aired by Iranian state media showed dozens of bloodied bodies strewn around with some bystanders trying to help survivors and others hurrying to leave the blast area.
"I heard a very loud sound and then felt pain in my back... then I could not feel my legs," a wounded woman at a Kerman hospital told state television.
Iran's Red Crescent rescuers tended to wounded people at the ceremony, where hundreds of Iranians had gathered to mark the anniversary of Soleimani's killing.
"A terrible sound was heard there, despite all the security and safety measures. The matter is still under investigation," Reza Fallah, head of the Kerman Red Crescent Society, told state television.
Later, the state news agency said the cemetery had been evacuated and closed until further notice.
The government announced that Thursday would be a day of mourning.
While the authorities did not publicly assign blame, the top commander of Iran's Quds force Esmail Qaani said the attacks were carried out by "the agents of the Zionist regime (Israel) and the United States".
Iran often accuses its arch enemies, Israel and the United States, of backing anti-Iran militant groups.
State TV showed crowds gathered at the cemetery at night, chanting: "Death to Israel" and "Death to America".
The United States was not involved in any way in the explosions in Iran on Wednesday and has no reason to believe Israel was, US State Department spokesman Matthew Miller told a regular news briefing.
In 2022, the Sunni Muslim militant group Islamic State claimed responsibility for a deadly attack on a Shi'ite shrine in Iran which killed 15 people.
Earlier attacks claimed by the group include deadly twin bombings in 2017 which targeted Iran's parliament and the tomb of the Islamic Republic's founder Ayatollah Ruhollah Khomeini.
Baluchi militants and ethnic Arab separatists have also staged attacks in Iran.
The US assassination of Soleimani in a drone attack at Baghdad airport and Iran's retaliation by attacking two Iraq military bases that house US troops brought the United States and Iran close to full-blown conflict in 2020.
As chief commander of the elite Quds force, the overseas arm of Iran's Revolutionary Guard Corps (IRGC), Soleimani ran clandestine operations in other countries and was a key figure in Iran's long-standing campaign to drive US forces out of the Middle East.
