Published June 27, 2015
The footage was posted on the day the historic legislation of same-sex marriage was passed in the US.
Twitter account @Raqqa_Sl, which campaigns to end the violence in Syria, tweeted photos from the execution in the Syrian city of Deir ez-Zor.
A video uploaded by the campaigners showed the men being forced to queue on a five-story building before being thrown over the edge.
No screams are audible as they fall to their deaths.
Hundreds of people living under the Islamic caliphate gathered to watch the brutal execution.
Spectators can be heard gasping in an atrocious scene as the men died one after another, with their corpses piling up on the ground.
Yesterday marked one of the greatest steps in gay rights history after a landmark Supreme Court decision making same-sex marriage a right for everyone in the US.
It has been suggested that the Islamic extremists flung four men from a rooftop before allowing them to plunge to their deaths to ‘celebrate’ the occasion.
Many ISIS extremists online were seen to ironically use the hashtag #LoveWins – a rallying tweet for gay rights campaigners across the globe.
The terror group have butchered a number of gay men in public executions within many of its strongholds in Syria.
Earlier this month ISIS killed another gay man after being hung by his feet from a roof.