"Intelligence systems were able to find good leads. A number of people involved in the attack have been detained, and information about them will be announced later by the security services," Vahidi was quoted as saying by Iranian news agency IRNA.
According to the latest official figures, 84 people were killed and 284 wounded on Wednesday by two explosions at the cemetery in Kerman where a crowd had gathered for a ceremony marking the fourth anniversary of Soleimani's assassination by US forces.
According to reports, two Daesh* militants detonated their explosive belts in the crowd.
Previous reports said that two bags with explosives were remotely detonated at the entrance to the cemetery.
Iranian news agency IRNA reported on Thursday, citing an informed source, that at least one of the blasts in Kerman was caused by a suicide bombing. The source said that evidence, including CCTV footage, showed that the first explosion was definitely caused by a suicide bombing carried out by a man.
The source also told the news agency that an investigation was underway to identify the bomber, whose body was ripped apart by the explosion, adding that an investigation into the causes of the second blast was also underway.
Later on Thursday, Daesh has claimed responsibility for the deadly terrorist attack on a morning procession for prominent Iranian general Qassem Soleimani in the Iranian city of Kerman
The Iranian government declared Thursday a day of national mourning for the victims, and the country's president, Ebrahim Raisi, who had postponed his planned visit to Turkey to deal with the issue, said the masterminds and perpetrators of the terrorist attack would be identified by security forces and law enforcement agencies and brought to account.
Soleimani, who commanded the Islamic Revolutionary Guard Corps' elite Quds Force, was killed by a US drone strike in Baghdad on January 3, 2020. Washington claimed he had been involved in organizing the attack on the US embassy in Baghdad on December 31, 2019. In response, Iran launched strikes on US bases in Iraq, including the al-Asad Airbase.
* Daesh (also known as ISIS/ISIL/IS/Islamic State) is a terrorist group banned in Russia and many other countries