The content originally appeared on: CNN CNN - Researchers at Yale University say they have uncovered 21 'filtration' sites in the Russian-controlled territory of Donetsk in eastern Ukraine. The researchers say these sites are used by Russian forces and their allies to process, register, interrogate and detain Ukrainians trying to leave Russian-occupied territory. Those detained can include civilians and prisoners of war. The Yale School of Public Health's Humanitarian Research Lab (Yale HRL) in collaboration with US State Department-supported Conflict […]