SHANGHAI - China’s port authorities will strengthen supervision of dangerous goods shipments following devastating explosions at Tianjin port last week, the Ministry of Transport said on Wednesday. Port authorities from provinces including Zhejiang, Liaoning and Guangdong have asked shipping firms involved in relevant activities to conduct self-inspections to check safety standards, and pledged to crack down on any illegal activities, according to a report posted on the ministry’s website. Over a hundred people have been killed by the blasts at a warehouse which stored hazardous chemicals at Tianjin Port. The Chinese owner of the warehouse did not a license to handle hazardous goods until two months before the disaster, according to its government-registered company records.