Two explosions caused by 'terrorist attacks' 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 said on Wednesday.

Iranian state television reported a first and then a second blast during an anniversary event at the cemetery where Soleimani is buried in the southeastern city of Kerman.

An unnamed official told the state news agency IRNA that "Two explosive devices planted along the road leading to Kerman's Martyrs' Cemetery were detonated remotely by terrorists".

Babak Yektaparast, a spokesperson for Iran's emergency services, was reported as saying 73 people had been killed and 170 injured. State television said later that at least 100 people had been killed.

No group has yet claimed responsibility for the attacks.

Videos aired by Iranian media showed dozens of bodies strewn around with some bystanders trying to attend to survivors and others hurrying to leave the blast area.

"A terrible sound was heard there, despite all the security and safety measures. We are still investigating," Reza Fallah, head of the Kerman Red Crescent Society, told state television.

Red Crescent rescuers tended to wounded people at the ceremony, where hundreds of Iranians had gathered to mark the anniversary of Soleimani's death. Some Iranian news agencies said the number of wounded people was much higher.

"We are now evacuating the wounded and injured in the area. The crowd is huge and the job is quite hard all the paths to there are blocked," Fallah said. (Reuters)