He urged rescuers not to give up on hopes, while leaving no single corner unchecked during the search and rescue mission.
Guo also urged a scrupulous plan to handle and clean up hazardous chemicals in a scientific way, so as to absolutely prevent any impacts on rescuers and nearby residents.
Chinese President Xi Jinping on Saturday urged authorities to learn from the "extremely profound" lessons paid for with blood.
Xi said in a written instruction that the Tianjin blasts and a string of serious accidents recently exposed severe problems in the work safety sector, and authorities must always keep "safe growth" and "people's interest first" in mind to avoid such accidents.
Premier Li Keqiang urged authorities to take forceful and effective measures to rectify the weak link so as to formulate a long-term mechanism to avoid the repetition of accidents.
The State Council on Saturday called a national tele-conference to lay out work on a national safety inspection that will target industries related with dangerous chemicals, explosives, fireworks, elevators, non-coal mines, public transport and ports.
ANGUISHED RELATIVES
Three days after the blasts, Wang Liying from neighboring Hebei province still heard no news on the fate of her 19-year-old son Yuan Xuxu, a firefighter working for the Tianjin Port Group Co..
Yuan and dozens of his colleagues were among the first to arrive at the site to handle the raging fire prior to the two huge explosions.
The mother made phone calls to her son immediately after learning the blasts, but could not reach him. She then rushed to Tianjin, but only learned that there was no news for any one among his son's 25-member brigade.
Efforts to look for her son at hospitals also was in vain.
On Saturday morning, she joined a group of family members of missing firemen to a hotel where a press conference was held, hoping to get any clue. They failed again.
"I just wish my son could come back alive," Wang told reporters in tears. She said her son earlier planned to go back home to see her in November.
"We want to see our son, no matter he was alive or dead, " said Liu Runwen. His 19-year-old Liu Zhiqiang was a colleague of Yuan.
"His mother cried for a whole day in the hotel and she is not in good health," said Li Fei, a cousin of fireman Liu. "The parents have been to several hospitals and got no news."
　　
