The parade was part of an annual commemoration known as the Sacred Defence Week celebrating the start of the Iran–Iraq War in 1980. It included the Islamic Revolutionary Guard Corps marching along Quds Boulevard in Ahvaz. 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); they also targeted a viewing stand and civilian bystanders.The attack lasted about ten minutes.
The attackers killed 25 people, including 12 soldiers of the Islamic Revolutionary Guard Corps and a four-year-old boy, with 70 others left wounded, including children. Many were taken to hospital in critical condition. The media initially reported that all four assailants were killed, but a fifth assailant was later also reported killed.