Drone footage has emerged showing police leading hundreds of blindfolded and shackled men from a train in what is believed to be a transfer of inmates in Xinjiang. The video, posted anonymously on YouTube last week, shows what appear to be Uighur Muslims or people from other minorities wearing blue and yellow uniforms, with shaven heads, their eyes covered, sitting in rows on the ground and later being led away by police. Prisoners in China are often transferred with handcuffs and masks covering their faces