Authorities of Hong Kong, Macau and Guangdong province have called for increased joint operations to combat narcotics following their efforts over the past 18 months, which have resulted in the arrest of 512 people and the seizure of 14.4 tonnes (31,746lbs) of drugs. Officials from mainland China’s central and local anti-drug authorities warned on Friday that the fight against narcotics had become more severe and complicated, with new technologies and types of drugs emerging. Hong Kong hosted...