Iraqi forces say they found a mass grave containing the remains of about 500 people at Badoush prison near Mosul yesterday. <br/><br/>Iraqi forces say they found a mass grave containing the remains of about 500 people at Badoush prison near Mosul yesterday. <br/><br/>The forces said, the victims were civilian prisoners killed by Islamic State, IS terrorists. The IS is alleged to have killed up to 600 inmates, most of them Shia Muslims, when it seized Mosul in 2014. Badoush prison was recaptured earlier this week.