A stampede has erupted at a funeral procession for a senior Iranian general killed in a US air strike last week, killing 56 people and injuring more than 200 others, according to reports.
The stampede took place in Kerman, the home town of Revolutionary Guard General Qassem Soleimani, as the procession began, said the semi-official Fars and ISNA news agencies, citing Pirhossein Koulivand, head of Iran's emergency medical services.
There was no information on what set off the stampede. Online videos showed people lying apparently lifeless, their faces covered by clothing. Emergency crews performed CPR on others.
"Unfortunately as a result of the stampede, some of our compatriots have been injured and some have been killed during the funeral processions," Mr Koulivand said.
State TV reported the death toll of 56, with 213 injured, citing Mr Koulivand,
Gen Soleimani's burial was delayed with no new time given. Authorities cited concerns about the massive crowd as a reason for the delay, ISNA said.
A procession in Tehran on Monday drew over a million people in the Iranian capital.
Gen Soleimani's death has sparked calls across Iran for revenge against America for a killed that has drastically raised tensions across the Middle East.
Early on Tuesday, the leader of Iran's Revolutionary Guard threatened to "set ablaze" places supported by the US over the killing, sparking cries from the crowd of supporters of "Death to Israel!"
Hossein Salami made the pledge before a crowd of thousands gathered in a central square in Kerman before a coffin carrying Gen Soleimani's remains.
The outpouring of grief was an unprecedented honour for a man viewed by Iranians as a national hero for his work leading the Guard's expeditionary Quds Force.
The US blames him for the killing of American troops in Iraq and accused him of plotting new attacks just before his death on Friday in a drone strike near Baghdad's international airport. He also led forces in Syria backing President Bashar Assad in a long war, and served as a go-between for Tehran in countries like Iraq, Lebanon and Yemen.
His killing has pushed Tehran to abandon the remaining limits of its 2015 nuclear deal with world powers as his successor and others vowed to take revenge. The Baghdad parliament has called for the expulsion of all American troops from Iraqi soil, something analysts fear could allow so-called Islamic State militants to mount a comeback.
Speaking in Kerman, Mr Salami praised Gen Soleimani's exploits, describing him as essential to backing Palestinian groups, Yemen's Houthi rebels and Shiite militias in Iraq and Syria. As a martyr, Gen Soleimani represents an even greater threat to Iran's enemies, he added.
According to a report on Tuesday by the semi-official Tasnim news agency, Iran has worked up 13 sets of plans for revenge for Gen Soleimani's killing. The report quoted Ali Shamkhani, the secretary of Iran's Supreme National Security Council, as saying that even the weakest among them would be a "historic nightmare" for the US, but declined to give any details.
"If the U.S. troops do not leave our region voluntarily and upright, we will do something to carry their bodies horizontally out," Mr Shamkhani said.
Iran's parliament passed an urgent bill declaring the US military's command at the Pentagon and those acting on its behalf in Gen Soleimani's killing as "terrorists" subject to Iranian sanctions.
The measure appears to be an attempt to mirror a decision by President Donald Trump in April to declare the Revolutionary Guard a "terrorist organisation".
The US Defence Department used the designation to support the strike that killed Gen Soleimani.
He will be buried later on Tuesday between the graves of Enayatollah Talebizadeh and Mohammad Hossein Yousef Elahi, two former Guard comrades. The two died in Operation Dawn 8 in Iran's 1980s war with Iraq in which Gen Soleimani also took part.