But residents questioned the tally and accused the authorities of negligence. “The toll is definitely much higher,” one relative of a missing person said at a temporary shelter.

A woman whose parents and brother were buried at home, said more than 10 people, including seven children, lived next door and none managed to escape.

“Nobody reported these missing cases on their behalf,” the woman said. “Nothing would be known of them until their dead bodies were dug out.”

Other witnesses said entire families of neighbours were buried, leaving no one to report them missing.

The catastrophe struck the Hengtaiyu Industrial Park in Guangming New District, Guangdong, on Sunday morning.

At least 33 buildings were battered or buried by the huge landslip that blanketed more than 380,000 square metres, according to the Shenzhen government.

Videos posted online by witnesses show a tide of mud unleashed across the park, leaving crushed factories and buildings in its wake.

FULL COVERAGE: Shenzhen landslide

The Ministry of Land and Resources said the landslide erupted after a 20-storey-high mountain of dumped earth and construction waste collapsed.

Liu Guonan, a geotechnical expert with the China Academy of Railway Sciences, said the disaster was the first of its kind to hit an urban area in China. “It’s the first time I have encountered a landslide of this nature on this scale in my 30-plus years in the field.”

President Xi Jinping and Premier Li Keqiang have called for all-out rescue efforts.

Shenzhen Communist Party boss Ma Xingrui and Shenzhen mayor Xu Qin returned from meetings in Beijing to oversee the rescue operation. The landslide occurred as party leaders met in the capital for a key conference on improving urban planning and management.

Last night, rescurers were carefully clearing away soil at several spots where signs of life had been detected. Firefighters were also guiding drivers in bulldozers trying to clear the debris.

Criticism also began to mount yesterday amid revelations that the licensed waste dump had been operating close to residential areas for two years despite a litany of complaints.

The dump was ordered to close five months ago, but continued to operate, according to documents published online by local authorities.

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The Cross-border Environment Concern Association, a Hong Kong-Guangdong non-governmental green group, said the site operated illegally from 2013 until it was granted an environmental permit in February.

“Satellite photos from 1990 to 2015 show a very clear trend of mountain erosion,” an association spokesman said. “Two major periods of damage occurred in 2002 when the site was built into a quarry and another one in 2014 when a natural vegetation barrier between the dump and the industrial Park was removed.”

Meanwhile, residents and migrant workers said there were concerns about the growing number of trucks delivering construction waste to the site, particularly in the rainy season, but the complaints fell on deaf ears.

CLP Power said it was notified on Sunday that the landslide had led to the temporary suspension of natural gas to Hong Kong because a section of a pipeline was damaged. The company made contingency arrangements to ensure electricity supply.