At least 45 ISIS militants reportedly died of food poisoning after breaking their fast (iftar) on Tuesday.
There are suspicions that the food may have been deliberately sabotaged, but the cause remains unknown.
The Kurdish Democratic Party of Iraq has confirmed that the poisoning took place in Mosul, Iraq.
Of the 145 people who gathered to break their fast at the iftar dinner in Mosul, Iraq, only 100 managed to survive.
This is not the first time that the group’s militants were poisoned with food, when dozens died back in November of last year after rebels of the Free Syrian Army (FSA) allegedly sneaked into their camp and contaminated their food.
Since the beginning of Ramadan, ISIS militants have frequently uploaded photos of them sitting down to feast on grand meals at the breaking-fast time for Muslims.
The men were seen in the photos sitting around their iftar spread adorned with fried fish, fruit, vine-leaves stuffed with rice, Pepsi cans among other appetisers.
Residents living under ISIS, however, are forced to feed off very scarce food resources, and eventually starve, according to the Daily Mail.
ISIS has become infamous for its bloody and inhumane executions, after its bloody insurgency began last year, leading to the flee of many ethnic groups who previously lived in the region.
ISIS is still controlling a swath of territory larger than Britain extending from eastern Syria to northern and western Iraq.