Iran observed a day of mourning Thursday for the at least 84 people killed when twin blasts ripped through a crowd commemorating the slain Revolutionary Guards general Qasem Soleimani.
The death toll was revised down from around 100 the day after what Iranian authorities labelled a "terrorist attack" that also left hundreds wounded near Soleimani's tomb in the southern city of Kerman.
No one claimed responsibility for the explosions in Iran, which has suffered deadly attacks in the past from jihadists and other militants as well as targeted killings of officials and nuclear scientists blamed on arch foe Israel.
The blasts ripped through crowds who had come to honour Soleimani, four years after a US drone strike in Baghdad killed the veteran senior commander of the Islamic Revolutionary Guard Corps.
Iran's supreme leader Ayatollah Ali Khamenei on Wednesday blamed "evil and criminal enemies" of the Islamic republic, without naming them, and vowed a "harsh response".
Regional tensions have surged amid the Gaza war sparked when Palestinian militant group Hamas launched their deadly October 7 attack on Israel, which Tehran welcomed while denying any involvement.
President Ebrahim Raisi's political deputy, Mohammad Jamshidi, charged on social media platform X that "the responsibility for this crime lies with the US and Zionist (Israeli) regimes, and terrorism is just a tool".
The United States rejected any suggestion that it or its ally Israel were behind the deadly blasts, while Israel declined to comment.
"The United States was not involved in any way, and any suggestion to the contrary is ridiculous," said State Department spokesman Matthew Miller.
"We have no reason to believe that Israel was involved in this explosion," he added, expressing sympathies to the victims of the "horrific" explosions and their families.
Soleimani, who headed the Guards' foreign operations arm the Quds Force, was also a staunch enemy of the Sunni extremist Islamic State group which has carried out attacks in majority-Shiite Iran.
- 'Desperate enemy' -
Regional tensions have surged amid the Gaza war, drawing in Iran-backed armed groups in Lebanon, Iraq, Syria and Yemen.
Hamas fighters infiltrated Israel on October 7, killing around 1,140 people, most of them civilians, according to an AFP tally based on official Israeli figures.
In response, Israel launched a relentless offensive that has reduced vast swathes of Gaza to rubble and claimed over 22,300 lives, according to the health ministry in the Hamas-run territory.
Iranian authorities called for mass protests over the Kerman blasts after weekly prayers on Friday, the day when local officials also said the victims' funerals will be held.
Revising down the death toll, Interior Minister Ahmad Vahidi cited forensic data and said "the number of martyrs... has been announced as 84 so far," official news agency IRNA reported.
Iran's emergency services chief Jafar Miadfar pointed to difficulties identifying dismembered bodies and said some victims were mistakenly counted "several times".
He said 284 people were wounded and "195 are still hospitalised".
Revered by many Iranians, Soleimani oversaw military operations across the Middle East, and millions came to his funeral in 2020.
Current Quds Force commander Esmail Qaani suggested the Kerman crowd was "attacked by bloodthirsty people supplied by the United States and the Zionist regime".
He pointed to two recent killings widely blamed on Israel -- a Beirut strike on Hamas deputy leader Saleh al-Aruri, and the killing near Damascus of senior Guards commander Razi Moussavi in December.
"The killing of Aruri and people like Razi Moussavi and the crime in Kerman show how desperate the enemy is," Qaani said.
Tehran regularly accuses its arch-foes Israel and the United States of inciting unrest in the country, and authorities last month executed five people convicted of collaborating with Israel.
In July, Iran's intelligence ministry said it had disbanded a network "linked to Israel's spy organisation" that it said had been plotting "terrorist operations" across Iran, IRNA reported.
In September, the Fars news agency had reported that an IS-affiliated key "operative", in charge of carrying out "terrorist operations" in Iran, had been arrested in Kerman.