The blasts occurred near the Saheb al-Zaman mosque in Soleimani’s southern hometown of Kerman, where he is buried, as supporters gathered to mark the fourth anniversary of his death in a US drone strike just outside Baghdad airport.
The deputy governor of Kerman said the explosion was a “terrorist attack”.
State media said at least 170 people were also injured in the bombings.
Iran’s Tasnim news agency quoted informed sources as saying, “Two bags filled with bombs exploded”.
“The perpetrators of this incident apparently detonated the bomb by remote control,” Tasneem said.
ISNA news agency quoted Kerman Mayor Saeed Tabrizi as saying that the bombs detonated 10 minutes apart.