IS Khorasan is the name of east Afghanistan's ISIS franchise.

Victims in the clip, called 'Khorasan the Graveyard for the Apostates 2', were captured members of the Taliban, according to the SITE group which monitors terror activity.

Analysts say that while the group's ultra-violent ideology has seen some success in Afghanistan and Pakistan, ISIS is still scrabbling for purchase in Pakistan largely due to competition from well-established extremist groups already there.

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