Meanwhile, seven or eight fresh blasts caused new fires to break out at the facility in the port city of Tianjin earlier in the day, the state news agency Xinhua reported. It did not give details about the scale of the latest explosions.

As the list of casualties count continued to grow, the Pope offered prayers in Rome for the victims and their families.

As of Saturday 10pm, the official body count from the disaster had risen to 104.

"Those who have lost their lives as well as all those touched by this catastrophe are in my prayers," Pope Francis said during angelus prayers at St  Peter's in Rome during the Catholic Feast of the Assumption, which marks Christ's mother Mary's ascent to heaven.

Starting from 11am, police and volunteers with loudspeakers were telling Tianjin residents to start evacuating the danger zone, The Beijing News reported on its news website.

However, some residents had reportedly returned later in the day after the wind direction changed again.

Police blocked Donghai Road, the main road leading to the blast zone. At the same, teams in vehicles were seen clearing paths for rescue efforts.

Special anti-chemical warfare troops were searching for survivors of Friday’s massive explosions as the confirmed death toll rose to 85 people, Xinhua said.

WATCH: Raw footage of the powerful explosions that rocked Tianjin on Wednesday evening

Thirteen firefighters and an unknown number of port workers were still missing, it said. One firefighter was rescued from the ruins of the warehouse early Friday morning.

The disaster started when two explosions with a combined force of 24 tonnes of TNT ripped through the industrial Binhai New Area, burning everything in its path and damaging infrastructure up to 1 kilometre away, including surround apartment blocks.

The death toll today rose to 85, and 721 people are in hospital - 25 in critical condition.

CCTV reported at noon that they found a male survivor, in his 40s, inside a shipping container 50 metres away from the "core zone" of the explosion and about 20 metres from a still-raging fire. He is currently being debriefed by authorities. 

At least 721 people were injured when explosions and a fireball hit the warehouse late Wednesday. Twenty-five were critically wounded and another 33 were in a serious condition, Xinhua said.

READ MORE: Tianjin blast death toll jumps to 85 as 'no-man zone' set up in Chinese city amid fears of toxic contamination

More than 1,000 rescuers were proceeding slowly in uncertain conditions where unidentified hazardous substances triggered the explosion, authorities said.

Armed police were carrying out the evacuation after highly poisonous sodium cyanide was found at the site, The Beijing News said, as the blaze intensified  dramatically, with several blasts reportedly heard.

“Out of consideration for toxic substances spreading, the masses nearby  have been asked to evacuate,” Xinhua said.

Officials said earlier that specialists from sodium cyanide producers were being sent in to the hazardous goods storage facility where giant explosions days earlier sent a huge fireball soaring into the sky and left a vast radius of destruction.

Authorities have struggled to control the resulting days-long blaze and  identify the substances present at the scene, sparking fears among locals.

Furious residents and victims’ relatives railed against officials outside a  news conference for keeping them in the dark as criticism over a lack of  transparency mounted. There were 21 firefighters among the dead, authorities said.

They were prevented from  entering the briefing and could be heard shouting outside.

“Nobody has told us anything, we’re in the dark, there is no news at all,”  screamed one middle-aged woman, as she was dragged away by security personnel.

Officials said they were unable to identify precisely what chemicals were  at the site at the time.

At the news conference, Tianjin work safety official Gao Huaiyou listed a  host of possible substances, adding that recent large exports that passed through the site had included sodium bisulfide, magnesium, sodium, potassium  nitrate, ammonium nitrate, and sodium cyanide, among others.

“We believe there should still be a lot stored at the terminal areas,” he  said.

Personnel from sodium cyanide producers had been called in “because they are experts on the chemical’s nature and the ways to deal with it”, he added.

A sewage pipe where the chemical had reportedly been detected had been sealed off, he said.
    
More than 200 nuclear and biochemical experts from the Chinese military were deployed to Tianjin, which has a population of 15 million, on  Thursday.

Concerns about the chemical cocktail also raised questions over whether firefighters responding to an initial blaze at the warehouse could have contributed to the detonations by spraying water over substances that react explosively to it.

One senior official insisted firefighters had followed the proper  procedures, but noted that they were unaware of the precise chemicals present  when they arrived.

“It is not clear whether a chemical reaction occurred,” said Lei Jinde, the head of the firefighting department at Tianjin’s public security bureau.

“We knew there was calcium carbide, but we don’t know whether the calcium  carbide exploded and caught fire,” he said in an interview published by Xinhua. “It is not that the firefighters were fools ... No, it is not that.”

Lei said that the facility was listed as holding ammonium nitrate and  potassium nitrate, as well as calcium carbide.

State newspaper The People’s Daily said earlier that the facility’s construction “clearly  violated” safety rules. Under Chinese regulations, warehouses stocking dangerous materials must be at least one kilometre away from surrounding public buildings and  main roads, it said, but there were two residential compounds and several main  roads within that distance.

INFOGRAPHIC: The toxic cocktail in warehouse at centre of fatal explosions in Tianjin, China

With additional reporting by Celine Sun