Four days after a bloody attack on a military parade in Iran's mostly Arab "Ahvaz" region, also known as Khuzestan, and conflicting claims of responsibility, questions remain over who was actually behind the attack.
More questions were raised than were answered Tuesday after Iranian media showed video of a group of over 20 people arrested for alleged involvement in Saturday's attack.
The Fars news agency named five alleged perpetrators, several of whom were killed, claiming that three of the men were brothers.
The country's Intelligence Minister Mahmoud Alawi vowed a stern response to the attack and insisted that all of the country's security forces were trying to uncover information on the attack.
Alawvi said the military and security forces, along with the Revolutionary Guard and police, will work until they identify all the culprits behind the attack and then punish them, delivering a message to the world that it will react in the face of what he called crimes against humanity.
The country's Supreme Leader Ayatollah Ali Khamenei, along with several Revolutionary Guard commanders, accused Saudi Arabia and the United Arab Emirates, along with the United States.
U.S. Defense Secretary Jim Mattis called the allegations "ludicrous," while Secretary of State Mike Pompeo denied the U.S. had any role in the attack. Pompeo told Fox News that it is an "enormous mistake" to "blame others when you have a security incident at home."
Former Iranian President Abolhassan Bani Sadr tells VOA that terrorism is increasingly an international phenomenon, so while it is unclear who was behind the Ahvaz attack, he doubts it could have happened without outside help.
Bani Sadr said that unless nation states or foreign powers support acts of violence, no independent organization, whatever it be called, can use violence for a long period of time."
Bani Sadr goes on to say that "everything has become internationalized, today." It has become very easy to send people to commit acts of terrorism anywhere in the world, including Iran or the U.S. He thinks that some international group "seeks to create instability" in order to "prevent any possible rapprochement between Iran and the West."
Khattar Abou Diab, who teaches political science at the University of Paris, calls the Ahvaz attack an "enigma," arguing that both internal or external forces could have been behind it.
He said that it is possible that a new separatist group is on the rise inside Iran and could be responsible for the attack, and that accusations against the UAE and Saudi Arabia are not new.
"The Iranian regime," he said, "is currently facing serious problems, given U.S. (economic sanctions), so it is not unlikely that [Supreme Leader] Ayatollah Khamenei would try to divert attention by making accusations against the U.S., Saudi Arabia and the UAE."
"Iran," Diab said, "is in a position now, where it needs to look like a victim."
Bani Sadr, however, thinks that the "Iranian people have reacted to the attack by rejecting violence.”
"All Iranian political factions," he argues, "are opposed to any kind of violence, including any 'retaliation' by [Ayatollah] Khamenei."