A SWAT unit officer patrols the Shanghai Railway Station Tuesday. To enhance public security during the ongoing 2014 Summer Youth Olympic Games in Nanjing, Jiangsu Province, the Shanghai railway police authority has increased the police presence at stations and trains. Every train bound for Nanjing now has at least one officer onboard, equipped with tear gas, handcuffs, a nightstick and a portable scanner. Photo: Yang Hui/GT