Hundreds of rescue workers are looking for survivors after a landslide hit 33 buildings in the southern Chinese city of Shenzhen.

Seven people were pulled from the rubble with minor injuries but 91 people are still missing, according to Shenzhen authorities.

About 900 people were evacuated from the industrial park as the landslide struck on Sunday.

The city is one of China's biggest and is a major industrial centre.

It is situated in the southern province of Guangdong, across the mainland border from Hong Kong.

The landslide has blanketed a vast area of 380,000 sq m (455,000 sq yards) covering it with up to 10m (32ft) of mud, Shenzhen's emergency management office said on its official microblog.

Reports said the landslide also caused an explosion at a nearby petrol station.

Local media reported initial investigations showed the landslide happened when a huge mound of soil and construction waste became unstable and collapsed.

People's Daily said the mound had accumulated at a stone quarry that had been converted into a dumping area with its entrance and exit facing an industrial district.

The incident took place around 11:40 (03:40 GMT) on Sunday morning in Guangming New District on the outskirts of Shenzhen city.

Residents evacuated from the surrounding area described hearing loud roars when the landslide happened.

Emergency officials said 33 buildings have either been buried or damaged to varying degrees.

They include three workers' dormitories, several factories and offices, a canteen, and other buildings.

State media quoted officials as saying 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.

President Xi Jinping has ordered local authorities to put all efforts into the rescue.