They are 12ers - those that believe the 12th imam that climbed into a well in the 7th Century will emerge when he smells enough blood - that being the blood of millions on millions dead.
He will they believe then lead a jihad across the world slaying all non-believers and the last two believers are obligated to kill each other - this is how the entire human race will enter Paradise.
“They are 12ers”
That’s only part of it.
They are saluting and declaring devotion to Khamenei, the Leader of the Islamic Republic of Iran. There is no separating the religious from the political.
This is Hezbollah training like in Lebanon, etc.