Militants disguised as soldiers opened fire on an annual Iranian military parade in the country's oil-rich southwest, killing at least 25 people and wounding over 60 in the deadliest terror attack to strike the country in nearly a decade.
Women and children scattered along with once-marching Revolutionary Guard soldiers as heavy gunfire rang out Saturday at the parade in Ahvaz, the chaos captured live on state television.
The region's Arab separatists, once only known for nighttime attacks on unguarded oil pipelines, claimed responsibility for the brazen assault and Iranian officials appeared to believe the claim.
Iran summoned diplomats from Britain, Denmark and the Netherlands early Sunday for allegedly harbouring "members of the terrorist group" that launched the attack.
Iranian Foreign Minister Mohammad Javad Zarif blamed regional countries and their "US masters" for funding and arming the separatists, issuing a stark warning as regional tensions remain high in the wake of the US withdraw from the Iranian nuclear deal.
"Iran will respond swiftly and decisively in defense of Iranian lives," Zarif wrote on Twitter.
The attack came as rows of Revolutionary Guardsmen marched down Ahvaz's Quds, or Jerusalem, Boulevard. It was one of many around the country marking the start of Iran's long 1980s war with Iraq, commemorations known as the "Sacred Defense Week."
"They were just aimlessly shooting around and did not have a specific target."
Meanwhile, Supreme Leader Ayatollah Ali Khamenei described the attack as exposing "the atrocity and viciousness of the enemies of the Iranian nation."
"However, to their dismay, the Iranian nation will persist on the noble and prideful path they have taken and will like before overcome all animosities."
Despite that, the U.S. government strongly condemned the attack and expressed its sympathy, saying that "the United States condemns all acts of terrorism and the loss of any innocent lives."
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