BEIJING, Aug. 15 -- Chinese leaders on Saturday urged authorities to learn from the "extremely profound" lessons paid for with blood as death toll from massive warehouse explosions in Tianjin rose to 104.

In a written instruction, President Xi Jinping said 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 development" and "people's interest first" in mind to avoid such accidents.

He demands a better emergency response mechanism, greater implementation of work safety regulations, and careful checks of all possible safety risks, to achieve "substantial improvement" in work safety.

The accountability system must be put into practice earnestly in order to prevent dereliction of duty, he added.

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.

The repeated emphasis on safety followed the massive explosions at a warehouse storing dangerous chemicals in north China's Tianjin City on Wednesday night, killing at least 104 people, and injuring more than 720.

The warehouse was owned by Tianjin Dongjiang Port Rui Hai International Logistics Co. Ltd., a storage and distribution center for containers of dangerous goods.

The State Council Work Safety Commission on Friday said the blasts revealed a lack of safety awareness among businesses, lax implementation of safety regulations, irregular practices among workers and weak emergency responses to incidents.