Complex sentence: A UN spokesman said that ISIS have broadcast dozens of videos showing beheadings, shootings and other cruel treatment of soldiers, police officers and civilians, with many people being targeted because of their ethnicity, particularly the Shiites and Christians.
Split into simpler sentences: A UN spokesman also reported that ISIS have broadcast dozens of videos showing beheadings, shootings and other cruel treatment of soldiers, police officers and civilians. I was reported that many of the victims appear to have been targeted because of their ethnicity, particularly Shiites and Christians.