Islamic State (Isis) released a video purportedly showing 21 captive Peshmerga fighters being paraded in cages through the streets of a town in Kirkuk province, Iraq, according to the SITE intelligence group.

The video, And Heal The Breasts Of A Believing People - the same title given to footage that showed Jordanian pilot Moaz al-Kasasbeh being burned alive - was distributed on social media websites on 21 February.

It does not show the execution of the men and they are alive at the end of the video but screen flashes show the beheading of 21 Egyptian Christians by Isis divisions in Libya.

The al-Malhama Brigade, a pro-IS jihadi media group, had distributed a video on 13 February containing similar scenes of the parading of caged Peshmerga but recorded from a different angle.

Peshmerga forces have been fighting IS in the Kurdish region of northern Iraq and trying to surround the city of Mosul to cut off Isis supply lines from Syria.

IS has caused international alarm by capturing large expanses of Iraq and Syria, declaring an Islamic "caliphate" and erasing borders between the two.