While Iranians in the province of Khuzestan held funeral processions for the victims of a terrorist attack on a military parade, there still seems to be a great deal of confusion in the media as to who was behind the attack, causing tension between Iran and a number of European countries. 

One day after the attack, the Islamic State (IS) released a video claiming responsibility for the attack that killed 29 people, including children and disabled veterans of the Iran-Iraq War. The IS-affiliated Amaq news agency released a video of the four perpetrators. Three of the attackers spoke Arabic into the camera as they drove in a car, dressed in military fatigues. One of the attackers spoke Persian, the predominant language in Iran. According to early reports, three of the attackers were killed on the scene and one was taken alive. It is not clear which man in the video was taken alive. 

IS is not the only group to take responsibility for the attack. European-based Arab separatist groups also attempted to claim responsibility, causing the wrath of Iran against their European host countries.

Yaqub Horr Tostari, who claimed to be a spokesman for the separatist Al-Ahvaz movement, called into a Saudi-funded London-based Persian-language station, Iran International, to take responsibility. Tostari said that a group called "the National Resistance of Ahvaz" carried out a “legitimate attack.” Tostari denied that his Al-Ahvaz movement was behind it but rather described the National Resistance of Ahvaz as an umbrella group. The Islamic Republic News Agency reported that the Patriotic Arab Democratic Movement in Ahvaz, a separatist group, had also taken responsibility.