ISIS has killed hundreds of men and children in Iraq, according to latest reports.
The terror group is said to have rounded up a total of 284 men and boys as Iraqi-led coalition forces closed in on Mosul, its last major stronghold in the country.
Those who have been killed over the course of two days are said to have been used as human shields against the coalition attacks.
The militant organisation is then believed to have left the bodies in a mass grave dug out at the now disused College of Agriculture in the north of Mosul. A bulldozer is believed to have been used to dig out the grave and dump the corpses.
All of the victims were shot said a source, who requested he remain anonymous because he has no authorisation to talk to media.
So far, the killings have not been independently authorised.
Along with those killed, a further 550 families are believed to have been taken hostage by Islamic State. While some have been allowed to go home, others are said to still be currently being used as human shields.
Families have been seen waving white flags as terrorists round up villagers in a last-ditch effort to stop coalition forces which are on the advance in the battle to take Mosul back from ISIS.
The deaths were made public by a source from the Iraqi intelligence service who said fears were growing for the safety of the hostages.
This latest attack comes just a day after ISIS launched attacks on the city of Kirkuk, including killing 15 women in an airstrike.
Meanwhile, ISIS fighters have been trying another method to slow the advance by deliberately setting fire to stockpiles of sulphur in a move which has killed civilians with toxic gas.
The region around the Mishraq Sulphur Plant was covered with a fog of yellow fumes as the fight continued to retain or gain control of Mosul.
ISIS is reported to have blown up the sulphur plant itself, killing two people among people living in surrounding villages.
Mosul has been governed since 2014 by ISIS which has led to the Battle of Mosul, a huge military offensive to try to seize back control of the city. The fight has seen the biggest deployment of Iraqi forces since the invasion in 2003 by US and coalition forces.