A video of the horrific act has emerged online, The Mirror online reported.
The footage, reportedly shot in ancient city of Palmyra, Syria, shows the savage execution of two Syrian men accused of being homosexuals.
Both the men were thrown off a roof and then stoned to death by the thugs of the caliphate. In the footage children were seen among the crowd.
Middle East Journalist Zaid Benjamin said on Twitter that the two Syrian men were executed for "having a homosexual affair."
According to reports ISIS has been using its fighters in honey traps to expose gay men and then kill them.
The group has created havoc since establishment of its caliphate. ISIS has executed 1,787 civilians, including 74 children and 86 women, by shooting, beheading, stoning, throwing from high places and burning.