Revolutionaries posing as cooks infiltrated an ISIS camp and poisoned meals in a bid to kill as many fighters as they could.
Sources in the Syrian Free Army said a dozen Islamic State militants perished after eating a contaminated lunch at the Fath El-Sahel camp, where 1,200 are based.
The rebels who hatched the plot were a group of defected Syrian soldiers who are fighting to overthrow President Bashar al-Assad.
The Times of Iraq reported that witnesses said around a dozen were killed and 15 transferred to nearby field hospitals.
The 'cooks' immediately fled, along with their families, with the help of fellow revolutionaries.