[3][14] Five gunmen began shooting at the parade from a nearby park on 22 September 2018 at 09:00 local time, wearing military uniforms and disguised as Islamic Revolutionary Guards Corps and Basiji (volunteers);[15] they also targeted a viewing stand and civilian bystanders.

[22] Initial reports conflicted; Iranian state media said all four assailants had been killed, while local deputy governor Ali Hosein Hoseinzadeh said two were arrested.

[16][23] Iran news agency's reports showed that three out of the four assailants were shot dead during the attack whereas the fourth died shortly later in the hospital, according to The Guardian.

[28][29] 22 September The claim of responsibility was first made through Iran International TV by Yaqoub al-Tostari, the spokesperson for the ASMLA who spoke to the television on air, on the same day.

[28] Amaq News Agency claimed that the Islamic State of Iraq and the Levant was responsible and posted videos of three men discussing the upcoming attack.

[13] The denial happened after Iranian foreign ministry summoned the ambassadors of Denmark and the Netherlands in Tehran and protested them for hosting ASMLA.

[36] 26 September On 26 September, ISIL's Al Furqan Media Foundation, which publishes official announcements from ISIL leaders, published an audio statement titled "The Muwahhidin's Assault on the Tower of the Mushrikin" from spokesman Abul-Hasan Al-Muhajir, which claimed "A group of men of the Khilafah and guardians of the creed in the land of Persia have pounced in defense of the religion, acting to deter and suppress their enemy and to fulfill the Islamic State's promise to all who have the blood of Ahlus Sunnah on their hands.

[38] Iran's Foreign Ministry spokesman Bahram Qassemi said that Abdulla's comments were "irresponsible and thoughtless" and "could hold Abu Dhabi accountable".

[41] Russian President Vladimir Putin said that he was horrified and presented his condolences, while the Syrian Ministry of Foreign Affairs strongly condemned the attack and warned those who finance terrorism in the region.

[46] The United Nations Security Council issued a statement condemning the terrorist attack and calling for the perpetrators to be brought to justice.

[47] General Hossein Salami of the Revolutionary Guard called Saudi Arabia, Israel, and the United States the "evil triangle".

[56] But according to Colonel Sean Ryan, spokesman for the US-led Combined Joint Task Force – Operation Inherent Resolve, the attack did no damage at all.

[59] On 6 May 2023, Habib Farajollah Chaab, a leader of the Arab Struggle Movement for the Liberation of Ahwaz, was executed by hanging after being accused of masterminding the attack.