Rescue workers are searching for survivors after a landslide hit 33 buildings in the southern Chinese city of Shenzhen.
Authorities said a huge man-made mound of earth and construction debris lost its stability and collapsed after being stacked too steeply.
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A wall of mud smashed into multi-storey buildings at the Hengtaiyu industrial park in the city's north-western Guangming New District on Sunday morning.
Seven people were found in the rubble suffering from minor injuries but 91 are still missing. About 900 people were evacuated as the landslide struck.
The Ministry of Land and Resources said in a post on their official Weibo site that they had sent a team to investigate and found that the accumulation of a large amount of waste meant that mud was stacked too steep, "causing instability and collapse, resulting in the collapse of buildings".
China's state broadcaster has also shown amateur footage of the disaster and reported that part of the major pipeline between the west of the country and the east has also exploded.
"The rushing mud was only 10 metres away from me," an unidentified man told the Shanghai newspaper The Paper, according to The Guardian. "As I ran out of the village with another youth, I heard a large explosion," he said.
State media quoted officials as saying that 59 men and 32 women were missing and that "signs of life" had been detected at three separate locations. Hundreds of rescue workers, police and special forces are at the scene helping with the operation.
This is another in "a series of industrial accidents this year" says the BBC's Juliana Liu and "questions are being raised about rapid industrialisation and safety standards" in the Guangdong province.
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