ISIS's security forces have forbidden mourning for those killed in clashes with Iraqi army, sources in the city of Mosul said. "Intensified indifferences among the ISIS's leadership in Mosul in Northern Iraq over ways of confronting consequences of their defeats in Fallujah and other battlefields have caused a large number of the terrorists and their families move to Raqqa in Syria," the sources said, adding, "The harsh policies of ISIS have annoyed even its own members, that is why they do not want to stay in Mosul any more." "The Takfiri group's fear of the news of its defeats and real number of their casualties has made them to decide to ban families of the killed members from mourning," the sources went on to say. The sources also said that there have been several cases of clashes in Mosul between ISIS forces and the families of those members who have been killed in the war following the ban. Reports said on Wednesday that an unknown group in the Northern city of Mosul initiated beheading the senior leaders of the ISIS terrorist group as Iraq's Joint Military Forces were preparing to launch an attack to take back the city. Ra'fat al-Zardari, the editor of Nineveh Journalists, said that a secret group called 'Armed Resistance' that is also known with its 'M' acronym has claimed responsibility for decapitating the ISIS leaders in al-Sarjkhaneh region. According to him, the group has fooled the ISIS leaders by the help of two kids to take them to Sarjkhaneh busy market and beheaded them after a surprise attack.