BEIJING
China has intensified investigations into a massive explosion that ripped through a warehouse in a northern port city, leaving 50 people including 17 firefighters dead.
State news agency Xinhua reported Friday that thick smoke -- possibly containing poisonous substances -- continued to cover the area near the warehouse reportedly storing dangerous and chemical goods in Tianjin city two days after the blast.
A heavy pungent smell could be detected around 1 kilometer away from the site, according to the agency, while people nearby complained of eye irritation.
A 19-year-old firefighter was rescued from the site Friday as rescue teams -- who have been ordered to wear heavy protective suits -- continued to search for 18 firefighters reported missing by the Ministry of Public Security.
After a team of 217 military specialists in nuclear and biochemical materials was deployed to Tianjin on Thursday, authorities told reporters the following day that the dangerous chemicals at the warehouse could not be determined at the moment.
Xinhua quoted Gao Huaiyou, deputy director at Tianjin's work safety watchdog, as saying that major discrepancies in the accounts of company management and customs, as well as damage to the company's office, contributed to the difficulty in identifying the chemicals.
The blast that tore through the Binhai New Area of Tianjin late Wednesday triggered a second explosion that sent fireballs into the sky, doors and windows flying in neighboring areas, and set cars and houses on fire.
Xinhua reported rescue headquarters as saying that 701 people have been hospitalized with injuries reportedly caused by broken pieces of glass, stone and iron.
Among the injured, 71 remain in a critical condition.
More than 1,000 firefighters and 140 fire engines continue efforts to put out the fire.
Zhou Tian, Tianjin fire department chief, told a press conference Friday that at the time of the explosions, several firefighters had been trying to battle the flames as backup forces “just arrived”.
“They were caught off guard, so the casualties are grave," he said.
The Yangtze River Daily reported on concerns that 700 tons of sodium cyanide in the area “could turn deadly poisonous” if it reacts with rain forecast for later Friday.
President Xi Jinping has urged all-out efforts to save the injured and minimize casualties, and rescuers continue to search for people trapped inside the site.
Xi underlined that the cause of the fire must be found.
The city is a 30-minute train ride from Beijing, and home to 14.72 million people, according to 2013 data from China National Bureau of Statistics.
