Militantst of the Takfiri group, ISIL, strung up four Iraqi fighters from the Popular Mobilization Forces and burned them alive, according to footage posted online

Militantst of the Takfiri group, ISIL (so-called Islamic State in Iraq and Levant) strung up four Iraqi fighters from the Popular Mobilization Forces and burned them alive, according to footage posted online, the latest gruesome execution video from the insurgents.

The victims were suspended from a swing set by chains attached to their hands and feet, then set on fire.

"Now retribution has come, for today, we will attack them as they attacked us, and punish them as they punished us," a masked militant says in the video, which was not dated and did not say where the burnings took place.

ISIL has carried out a slew of atrocities in territory it controls in Iraq and Syria, such as mass executions and a campaign of killings, kidnapping and rape targeting minorities.

It has recorded many killings -- including beheadings, shootings, drowning and burnings -- in videos posted online.