State television blamed “takfiri elements”, a reference to militants for the attack.
Iranian foreign ministry spokesman Bahram Qasemi said Iran “asked their governments to condemn the attack and extradite people linked to it to Iran to be put on trial”.
Within an hour of this statement, Iran’s Foreign Ministry summoned the United Arab Emirates charge d’affaires to rebuke him for comments made by an unnamed Emirati official.
Iran has intervened in the wars in Syria and Iraq and plays an influential role in Yemen, but this was a rare attack on its own soil. “It is the Americans who incite them”, he said.
The Islamic State group also claimed responsibility for the attack, but provided no evidence it carried out the assault.
Gunmen disguised as soldiers in military uniforms, began shooting from behind the stands during the parade, according to the state-run news agency.
The al-Ahvaziya terror group, whose members are believed to be scattered across several European countries, claimed responsibility for the attack.
Saturday’s attack, in which militants disguised as soldiers opened fire on an annual Iranian military parade in Ahvaz, was the deadliest attack in the country in almost a decade.
Most of the victims are women and children watching a parade commemorating the 30th anniversary of the outbreak of the Iran-Iraq war.
The terror outfit, which is backed by Saudi Arabia, has a record of carrying out sabotage acts in Khuzestan province, which encompasses Ahvaz and some other towns with Arab population.
Tensions have been on the rise between Iran and the US.
Only a year ago, Saudi Crown Prince Mohammed bin Salman explained in an interview that Saudi Arabia would take the fight to “inside Iran”.
“It is absolutely clear to us who has done this, which group it is and to whom they are affiliated”, Rouhani said on state television on Sunday, shortly before leaving Tehran for the United Nations General Assembly in NY.
Senior commanders have said the Ahvaz attack was carried out by militants trained by Gulf states and Israel and backed by America.
President Trump is open to meeting with Iranian leaders at this week’s UN General Assembly meeting, Pompeo said.
“These individuals affiliated with the United States and Mossad committed [the attack]”, he said.
Rouhani said as long as Saddam was alive, the group used to be a mercenary of the former Ba’ath regime, but they switched their fealty to a “southern Persian Gulf state” which has undertaken to provide the terrorists with funds, weapons and political assistance.
There was no immediate Gulf Arab comment on his remarks.
Iran’s Supreme Leader, Ayatollah Ali Khamenei, also called the attack a “continuation of the plots of the regional states that are puppets of the United States”.
“On behalf of #PADMAZ organization we reject all accusations and we insist that PADMAZ organization is a civil political movement and has nothing to do with what (happened) today in #IranMilitaryParade attack”, the group, using its acronym, said on unconfirmed Twitter and Facebook accounts.
Such attacks tend to unite Iranian reformers and hardliners despite sharp differences over domestic and foreign policies.
Iran faces pressure to swiftly respond to the high-profile attack, which has hurt the security establishment’s prestige.
The terrorist attack, which was first claimed by an Arab separatist group with alleged connections to Saudi Arabia, the Ahvaz National Resistance, did not occur in a vacuum.
“They call themselves Arab nationalists but we know they have very intimate ties to the Mujahedin-e-Khalq”, he said referring to an Iranian exiled dissident group accused of killing thousands of Iranian civilians and officials.
But in a statement on its website, the group denied any involvement, accusing Iranian authorities of ordering the attack to distract from Tehran’s support for “militias in the region”.