While the cause of the Tianjin blasts is still unknown, executives of the company that owns the warehouse at the center of the explosions have admitted to using their political connections to skirt safety regulations that prohibit the storage of hazardous chemicals too close to residential areas. The company was storing at least 2,500 tons of hazardous chemicals at the warehouse when it caught fire, including 700 tons of sodium cyanide, as well as ammonium nitrate and potassium nitrate. According to state media, firefighters there were unaware that some of the chemicals can ignite upon contact with water. The resulting explosions killed dozens of firefighters, damaged about 17,000 homes and raised fears of chemical contamination across Tianjin.

State news media reported Friday that four new fires had broken out at the blast site in Tianjin, just hours after Chinese officials said safety hazards were found at nearly 70 percent of companies handling dangerous chemicals in Beijing, while more than 100 chemical firms have been ordered to suspend operations or shut down because of safety violations in recent days.