SHENZHEN, June 26, 2016 (Xinhua) -- A drug-sniffing dog goes through obstacles during training at a detachment of the provincial border defense corps of south China's Guangdong Province, June 26, 2016. Sunday marks the International Day against Drug Abuse and Illicit Trafficking. Drug-sniffing dogs are a key force in fighting against illicit drug dealing. (Xinhua/Liao Jian)