Tehran — Iran's state-run IRNA news agency said 24 people were killed and 53 wounded in an attack on a military parade in the country's oil-rich southwest.
The agency cited "knowledgeable sources" without elaborating. It said gunmen were dressed in Guard uniforms and targeted a riser where military and police commanders were sitting.
The attack left at least eight members of the country's elite Revolutionary Guard dead and 20 others wounded, local media reported.
No group immediately claimed responsibility for the assault in Ahvaz, which saw gunfire spray into a crowd of marching Guardsmen, bystanders and government officials watching from a nearby riser
Iran's foreign minister blamed regional countries and their "US masters" for an attack on a military parade that killed at least eight people.
Mohammad Javad Zarif on Twitter also warned that "Iran will respond swiftly and decisively in defense of Iranian lives" after the attack in Ahvaz.
Zarif said that children and journalists were casualties in the attack.
He added that the gunmen were "terrorists recruited, trained, armed & paid by a foreign regime."
He did not immediately elaborate. However, Arab separatist groups in the region have launched attacks on oil pipelines there.