The terrorist group's latest barbaric video shows a large crowd gathering to watch the bloody execution of the men it claims are soldiers fighting for Syrian Army.
They are all marched to a small wooden stump and instructed to kneel, before an ISIS militant carries out brutal retaliation by taking their heads off with a sharpened blade.
The shocking video surfaced on ISIS' vast social media channels shows sickening footages of brutal ISIS guillotine punishment.
In video they says the execution is 'qisas' - or retaliation - for their alleged attack and imposed by the "Islamic court" for 'waging war on God and his messenger'.
Aymenn Jawad Al-Tamimi - a Research Fellow at the Middle East Forum at Kings College London - translated the militant's speech for MailOnline.
In front of the amassing crowd he says: 'Whoever kills the Muslims and spills their blood, their reward is slaughter.'
Al-Mayadin is one of two locations where ISIS has opened 'recruitment offices' to induct children into their ranks, according to the Syrian Observatory for Human Rights (SOHR).
It reported that as of March 23 at least 400 young children from the city and nearby al-Bokamal had joined the terrorist group's Ashbal al-Khilafah, 'the cubs of the caliphate'.