Thousands of residents scrambled to leave apartment buildings within a three-kilometre (two mile) radius of the explosion site in the northern Chinese port city of Tianjin on Saturday after fresh blasts were heard in the city, state media reported.
"At around 11.40 [Saturday] morning, fires in the blast site reignited and thick smoke poured out," state broadcaster CCTV said on its official account on the Twitter-like service Sina Weibo.
"Seven or eight explosions were heard, and fire broke out in at least three places, and there is pretty thick smoke across the whole area," it said.
State media showed chemical warfare troops in full protective gear looking for survivors, drone shots of the devastated container port, and officials going from building to building ordering residents to leave within a three-kilometer exclusion zone.
The death toll rose to 85 on Friday night, while official media said more than 700 people were injured in the explosions in a container port and warehouse area used to store dangerous chemicals, the official Xinhua news agency said.
Earlier figures compiled by RFA suggest that more than 1,200 people were hospitalized for injuries from burns and flying glass and debris, however.
Some 6,000 evacuees whose homes had been damaged by Wednesday's massive explosions are already billeted in schools in the city。
Officials say it is "possible" that sodium cyanide is present at the scene, after local residents near the disaster site told RFA on Friday there was a pervasive "bitter smell" often linked to the hazardous chemical, which is fatal if inhaled or ingested.
Gao Huaiyou, vice head of the Tianjin administrative bureau of work safety, told reporters that further confirmation is still needed, Xinhua news agency reported. Guo declined to confirm earlier reports that as much as 700 tonnes of sodium cyanide had been stored at the site of the explosions.
"Measures have been taken to prevent secondary disasters, such as inviting sodium cyanide producing enterprises to help at the site, using hydrogen peroxide to reduce the amount of sodium cyanide, sending a special taskforce to locate and measure the area contaminated by sodium cyanide, and prevent its spreading in sewage," Xinhua said.
Vague health warnings
However, health warnings from China's health authorities were somewhat vague.
"After breathing in ashes, some people's respiratory systems might have problems," vice minister for health and family planning Cui Li warned in comments reported by Xinhua.
"There are so many other factors such as the shock, panic and psychological disorder that occurred after the explosion took place," he said.
Emergency and specialist medical teams are being sent in to Tianjin to help local hospitals with the massive influx of injured, the agency said.
The ruling Chinese Communist Party has kept up tight controls on any reporting of the Tianjin disaster, ordering media organizations to use only approved copy from Xinhua and CCTV.
Comments, photos or information about the blasts or their aftermath are quickly deleted, and hundreds of social media accounts have been shut down for allegedly "spreading rumors" from Tianjin, officials said.
China's draconian Internet agency, the Cyberspace Administration, said it had suspended more than 360 social media accounts since the blasts rocked Tianjin.
"Certain accounts on microblogging site Sina Weibo and the instant messaging service WeChat began posting rumors like 'toxic gas blown to Beijing,' 'malls and markets looted,' and 'no one survived within one kilometre of the blast site,'" the administration said.
It also hit out at China's online celebrities, known as "Big V" bloggers, for posting "irresponsible" comments about the blast, including those likening the cloud over Tianjin to a mushroom cloud, or to Hiroshima.
"Rumors have never really had much of an impact on China," said Zhang Weiguo, former editor of the Shanghai-based World Economic Herald and currently editor-in-chief of Hong Kong's The Trend political magazine.
"They are just using rumors as an excuse to shut down and purge [unwanted reports]," he added.
Quixotic fight to repress comments
Zhang said tight government controls on online freedom of expression means the government has to work to limit damage on two fronts, whenever there is a natural disaster.
"On the one hand, they have to deal with the disaster, and on the other, they have to fight public opinion, which is why they try to shut it down."
"But you can't shut down the entire Internet; it's like Don Quixote and his windmills."
A Chinese blogger and writer who asked to be identified only by his surname, Li, said several of his friends' social media accounts had been suspended or shut down in recent days.
"The deletion and closure of accounts is incredibly strict right now," he said. "Anything remotely sensitive is being deleted, and a lot of websites have been tightly restricted."
"Rumors exist, but what the government really cares about, and what it is deleting and shutting down, is opinion; that's their focus," Li said.
He said there was a profusion of social media content in the immediate wake of the Tianjin disaster.
"When this story was breaking, the general public provides huge amounts of material, posting video and photos they have shot at the scene themselves," Li said.
"Others post detailed accounts, including maps, of the situation for local residents near the scene, while the Tianjin municipal government didn't provide the most basic information until four hours after the event," he said.
"Ordinary citizens are far, far quicker than the government."
Reported by Shi Shan for RFA's Mandarin Service, and by the Cantonese Service. Translated and written in English by Luisetta Mudie.