ISIS rounded up and killed 284 men and boys as Iraqi-led coalition forces closed in on Mosul, the terror group's last major stronghold in Iraq. <br/><br/>An Iraqi intelligence source told CNN that those killed on Thursday and Friday were used as human shields against attacks forcing ISIS out of southern parts of Mosul. <br/><br/>Intelligence Source said, the victims, some of them children, were all shot and <br/>ISIS dumped the corpses in a mass grave at the defunct College of Agriculture in northern Mosul.