Referring to a string of political and military heavyweights toppled by president Xi Jinping ’ s war on corruption , the newspaper added : “ If big cases such as those involving Zhou Yongkang , Xu Caihou , Guo Boxiong and Ling Jihua were thoroughly investigated in an open manner , why should there be cover-up over a safety accident ? ” The newspaper ’ s insistence came after a third day of protests in Tianjin over the government response to Wednesday ’ s explosions , which followed a blaze at a warehouse storing hazardous chemicals .