Islamic State group's Amaq agency has posted a video of three men in a vehicle who it said were on their way to carry out an attack on an Iranian military parade.
Two of the men spoke in Arabic about jihad, while the third spoke in Farsi suggesting they were targeting Iranian Revolutionary Guards, according to the recording, released after Saturday's assault on the Revolutionary Guards in the Iranian city of Ahvaz.
However, the video is not conclusive proof that the Islamic State group has carried out the attack. Iran has not released the identity of the attackers and there is no way to be certain that the individuals in the IS video are the perpetrators of the attack.
Initially, the Ahvaz National Resistance, an ethnic Arab group also claimed responsibility but they have not provided any proof so far.
Iran has officially announced that four gunmen carried out the attack, but the IS video does not mention the fourth assailant.
In the early hours after the attack Iran had claimed that one of the attackers was captured alive. Later, that version was changed and it was announced that all the gunmen were killed.
The Islamic State group claimed responsibility for a bloody attack on the Iranian parliament in June 2017 and issued videos of the attackers. At the time, Iran said that "Takfiri" elements organized the attack; a term reserved for Sunni militants.
Shortly after the attack, Iran's Islamic Revolution Guard, IRGC launched missiles at a militant target in Syria.