Islamic State of Iraq and Syria (ISIS) terrorist group has released a disturbing video which shows the brutal beating of fellow fighters for smoking cigarettes.

The new video shows militants lined up and sitting against a wall under an IS flag while a masked militant begins brutally beating them, even jabbing them with the barrel of his rifle.

The video shows a masked militant stomping on the men, who vainly try to defend themselves from the blows raining down. One of the men is also bashed by the fellow fighter on his head with the wooden butt of the weapon. The men are also seen whipped with a belt, according to the Daily Mirror.

ISIS prohibits smoking under strict Islamic rules and considers the habit a "slow suicide." The militant group has burned millions of cigarette packs in Iraq and Syria to enforce the ban on smoking.

Anti-ISIS group Raqqa is Being Slaughtered Silently head Abu Mohammad Hussam described the punishment to The Independent. "The first time he will be arrested and flogged (40 lashes). If he smokes again, he will be whipped and imprisoned. On the third occasion, he will be taken to a camp in the countryside and fined a large sum of money," he said.

The release of video follows a senior IS commander being found decapitated with a cigarette hanging from his mouth in February earlier this year. The words "O Sheikh this is munkar" were written on his body, according to the Syrian Observatory for Human Rights.

ISIS's strong opposition to smoking has led to decline in the tobacco business in the Middle East. U.K. tobacco giant Imperial Tobacco said 2 percent of the 5 percent fall in sales in the last quarter was due to the deteriorating political and security situation in Iraq, according to the Independent.