Militants shot dead at least 29 people including women and children at a military parade in southwestern Iran today, state media reported, in a rare attack the government blamed a US ally in the region.

There was no immediate claim of responsibility for the shooting rampage dubbed a ‘terrorist' attack by the authorities, in which at least 53 people were also wounded. But Foreign Minister Mohammad Javad Zarif said he held a US ally in the region responsible. “Terrorists recruited, trained, armed & paid by a foreign regime have attacked Ahvaz,” Zarif said in a tweet, adding: “Iran holds regional terror sponsors and their US masters accountable for such attacks”.
The deadly shooting targeted the city of Ahvaz in Khuzestan, a province bordering Iraq that has a large ethnic Arab community and has seen separatist violence in the past which Iran has blamed on its regional rivals.
“The number of martyrs of the terrorist incident reached 29, some of whom were women and children among the spectators,” IRNA said, adding the death toll could rise further as many of the wounded were in critical condition. 
Armed forces spokesman Brigadier General Abolfazl Shekarchi said that the dead included a young girl and a former serviceman in a wheelchair.
“Of the four terrorists, three were sent to hell at the scene, while the fourth who had been wounded and arrested went to hell moments ago due to his severe wounds,” Shekarchi told state television.
Khuzestan deputy governor Ali-Hossein Hosseinzadeh told the semi-official ISNA news agency that a journalist was also among the dead. He also said earlier that ‘eight to nine' troops had been killed.
Zarif did not specify which regional government he held responsible for the shooting, but Iran's elite Revolutionary Guards said the attackers were funded by Sunni arch rival Saudi Arabia. “Those who opened fire on civilians and the armed forces have links to the Ahvazi movement,” Guards spokesman Ramezan Sharif told ISNA. “They are funded by Saudi Arabia and they attempted to cast a shadow over the Iranian armed forces.” Zarif vowed Iran would ‘respond swiftly and decisively in defence'.
In a message of condolence to Russia's close regional ally, President Vladimir Putin said he was ‘appalled by this bloody crime.' “This event once again reminds us about the necessity of an uncompromising battle against terrorism in all of its manifestations.”.
Khuzestan was a major battleground of the 1980s war with Saddam's Iraq and the attack on the anniversary parade in Ahvaz had significant symbolic value. The province saw unrest in 2005 and 2011 but has since seen been largely quiet..
The attack in Ahvaz came as Iranian President Hassan Rouhani was among the dignitaries at the main anniversary parade in Tehran.
In a keynote speech, Rouhani vowed to boost Iran's ballistic missile capabilities despite Western concerns that were cited by his US counterpart Donald Trump in May when he abandoned a landmark nuclear deal with Tehran. “We will never decrease our defensive capabilities... we will increase them day by day,” Rouhani said at a military parade. “The fact that the missiles anger you shows they are our most effective weapons,” he said, referring to the West.