Deadly explosion rocks Tianjin in northern China

Huge explosions at a warehouse for dangerous materials in the northeastern Chinese port of Tianjin killed more than 40 people, injured hundreds and sent massive fireballs into the night sky, Chinese state media reported Thursday.

China's official Xinhua News Agency reported that 66 people were in critical condition and 520 had been hospitalized. Twelve firefighters were among the 44 people reported dead. 

Police in Tianjin said an initial blast took place at shipping containers in a warehouse for hazardous materials owned by Ruihai Logistics, a company that says it is properly approved to handle such materials. State media said senior management of the company had been detained by authorities, and that President Xi Jinping has demanded severe punishment for anyone found responsible for the explosions.

Xinhua said an initial explosion triggered other blasts. The National Earthquake Bureau reported two major blasts before midnight, the first with an equivalent of 3 tons of TNT, and the second with the equivalent of 21 tons.

The explosions took place in a mostly industrial economic development zone, with some apartment buildings in the vicinity. Buildings of a half-dozen other logistics companies were destroyed in the blasts, and more than 1,000 new cars were left charred in a nearby parking lot, the Beijing News said.

"I thought it was an earthquake, so I rushed downstairs without my shoes on," Tianjin resident Zhang Siyu, whose home is several miles from the blast site, said in a telephone interview with the Associated Press. "Only once I was outside did I realize it was an explosion. There was the huge fireball in the sky with thick clouds. Everybody could see it." 

Zhang said she could see wounded people weeping. She said she did not see anyone who had been killed, but "I could feel death."

Photos circulating online show a gigantic fireball and a mushroom-cloud. Videos of the explosion showed flames lighting up the night sky. Xinhua quoted residents in nearby districts as saying the blast had shattered windows. Videos posted on Weibo, a Chinese social network, showed a fireball shooting into the air and at least two separate explosions.

State broadcaster CCTV says six battalions of firefighters brought the ensuing fire under control. It says the firefighters were combing the neighborhood for possible injured residents.

Chinese Premier Li Keqiang "vowed thorough investigation of the accident and ensure open and transparent information disclosure to the public," one Xinhua article on the blast said. 

China has a dismal industrial safety record as some owners evade regulations to save money and pay off corrupt officials to look the other way.

In July fifteen people were killed and more than a dozen injured when an illegal fireworks warehouse exploded in the northern Hebei province. And at least 71 were killed in an explosion at a car parts factory in Kunshan, near Shanghai, last August.

Tianjin, which lies about 90 miles southeast of Beijing, is one of China's biggest cities, with a population of nearly 15 million people according to 2013 figures. A manufacturing center and major port for northern China, it is closely linked to Beijing, with a high-speed train line cutting the travel time between the cities to 30 minutes.

As is customary during disasters, Chinese authorities tried to keep a tight control over information. Police kept journalists and bystanders away with a cordon about a mile from the site. On China's popular microblogging platform of Weibo, some users complained that their posts about the blasts were deleted, and the number of searchable posts on the disaster fluctuated, in a sign that authorities were manipulating or placing limits on the number of posts.

Al Jazeera and wire services