Update as of 5:37 a.m. EDT: At least 21 people remain missing, after explosions rocked the Chinese city of Tianjin late Wednesday, according to a report from Chinese state media.

The death toll from the blast remains at 44, including 12 firefighters who lost their lives tackling the fires caused by the blasts. Of the missing, 18 are firefighters, Xinhua reported.

While the fires in the city are now for the most part under control, the Chinese government has ordered further firefighting efforts be suspended to allow a team of chemical experts to assess hazardous materials on site, dangers to the environment and how best to proceed, according to the Associated Press.

Xinhua also reported, citing a city official, that 149 of the people injured in the explosions have been transferred to larger hospitals, including 12 who are in critical condition.

Update as of 1:36 a.m. EDT: The death toll from the explosions that shook the Chinese city of Tianjin late Wednesday has risen to 44, state media reported Thursday. In addition, 66 people are now reported to be critically injured as a result of the blasts, with a total of 520 people hospitalized.

Reports on social media suggest that authorities in Tianjin have warned that further blasts in the city were possible, as emergency services battle fires started by the blasts. People in some areas of the city were reportedly asked to evacuate for their own safety.

Update as of 11:26 p.m. EDT: Chinese authorities have announced that 9 firefighters are among those killed by explosions in the city of Tianjin which occurred late Wednesday.

Authorities have lost contact with 36 firefighters at the scene the Tianjin fire department said, according to Chinese media reports. The explosions have left at least 17 dead, and hundreds wounded.

It is unclear whether the 9 firefighters are included in the death toll, or are an addition to it.

Original story:

At least 17 people have been killed and over 400 are injured, many critically, after a series of explosions rocked the Chinese city of Tianjin. State media reported that the blasts happened in a warehouse storing "dangerous and chemical goods" in the port area of the city.

The initial blast took place around 11:50 p.m. Wednesday (11:50 a.m. EDT). Pictures and footage shared on social media showed a huge fireball rising from the blast, which could reportedly be felt from several miles away, and was strong enough to be picked up by a weather satellite orbiting the Earth.

Warning – the video below contains scenes of bodily injury.

Over 100 fire engines were reportedly responding to the explosions, and four firefighters have been reportedly been injured, while two have been “out of contact” since 3 a.m. local time, China's state-run Xinhua news agency reported.

Chinese President Xi Jinping and Premier Li Keqiang have called for all-out efforts to assist the injured and minimize casualties from the blast. The State Council, China's cabinet, dispatched a work group led by Minister of Public Security Guo Shengkun to direct rescue and emergency response, Xinhua added.

Emergency services in the city are reportedly overwhelmed, as hundreds of injured people crowded into hospitals in emotional scenes. New York Times reporter Andrew Jacobs said on Twitter that grief stricken relatives outside a hospital in Tianjin attacked foreign journalists shouting "stop the foreigners from reporting."

China's CCTV News reported that local volunteers were gathering at hospitals to offer assistance to those injured in the blasts.

“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, told 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,” the agency added.

Tianjin explosions Rows of burnt out Volkswagen cars are seen near the site of a series of explosions in Tianjin, northern China on August 13, 2015. A series of massive explosions at a warehouse in the northern Chinese port city of Tianjin killed 17 people, state media reported August 13, as witnesses described a fireball from the blasts ripping through the night sky. Photo: AFP / Getty Images

One witness, cited by the BBC, named only as Ms. Yang, told local media she was out shopping when "suddenly from behind there was a big fireball and explosion."

"At the time of the explosion the ground was shaking fiercely, nearby cars and buildings were shaking, a few buildings' glass all broke and everyone started to run," she said.

"Now all the residents are gathered in the street."

Authorities told residents that it was “still safe to breathe” at the scene of the explosions, in an apparent attempt to address online fears that the blasts may have poisoned the air.