At least 44 people are now known to have died, and more than 500 injured, following two major explosions in China’s northern port city of Tianjin.
Twelve firefighters were among the dead, China’s official Xinhua news agency said as it reported a doubling of the death toll.
Two blasts happened in a warehouse storing “dangerous and chemical goods” in the port area of the city.
They caused a huge fireball that could be seen from space.
Buildings within a 2km radius (1.5 miles) had windows blown out, office blocks were destroyed and hundreds of cars burnt-out.
Images on Chinese media showed local residents and workers fleeing their homes, some of them covered in blood from broken glass and flying debris.
As of 12:00 local time (04:00 GMT), 44 people had died and a total of 520 people had been hospitalised, including 66 in a critical condition, Xinhua reported.
At the scene: John Sudworth, BBC News, Tianjin
The apartment complex closest to the explosion has eight rows of high-rise tower blocks.
In every one of them, almost every window has been blown out. On the ground outside are the signs of the many families who have fled from their beds in a hurry – a woman’s shoe, children’s toys, mangled bicycles.
There would have been many injured here. Inside the homes, furniture has been picked up as if by a whirlwind and interior doors lie at angles, ripped off their hinges.
The first explosion occurred at about 23:30 local time (15:30 GMT) on Wednesday, followed seconds later by another, more powerful blast and a series of smaller explosions.
The impact of the blasts could be felt several kilometres away, and was registered as seismic activity at a US Geological Survey monitoring unit in Beijing 160km (100 miles) away.
The China Earthquake Networks Centre said the magnitude of the first explosion was the equivalent of detonating three tonnes of TNT, while the second was the equivalent of 21 tonnes.
“It was like what we were told a nuclear bomb would be like,” truck driver Zhao Zhencheng told the AP news agency. “I’ve never even thought I’d see such a thing. It was terrifying, but also beautiful.”
The blast ripped apart a nearby dormitory for migrant workers, who were forced to flee the collapsing building.
“I rolled off the bed after the first shockwave hit, so I scrambled to run for my life.,” said resident Dan Agio.
“When I reach downstairs the second blast happened. It’s as if the sky collapsed. In a blink of an eye, the roof fell.”
One woman said a number of people in her apartment block were injured by glass blown out of windows, some suffering “considerable wounds”.
Around 1,000 firefighters, along with 140 fire engines, spent the night tackling the flames.
A number were reportedly already on the scene at the time of the explosions, having been called out to earlier reports of a fire in the area.
There was an outpouring of support for them on social media, amid reports that 36 firefighters remain missing, and a further 33 are being treated in nearby hospitals.
State broadcaster China Central Television (CCTV) said a shipment of explosives had detonated, causing the massive blasts, but this has not yet been confirmed.
Senior managers of Ruihai Logistics, which owns the warehouse where the explosion happened, are being questioned by authorities, state media report.
President Xi Jinping has promised a thorough investigation in what happened and “transparent information disclosure to the public,” Xinhua reports.
There has been some criticism in Chinese media that a warehouse containing such dangerous chemicals should have been sited near a main road, housing complexes and office blocks.
Tianjin, home to some 15 million people, is a major port and industrial area to the south-east of the Chinese capital, Beijing.
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