A landslide in southern China that killed two people and left more than 70 people missing was caused by breaches of construction safety rules and was not a natural disaster, a government website quoted local authorities as saying Friday.

An investigation by a team in Shenzhen, directed by China's Cabinet, found that the Dec. 20 disaster stemmed from waste construction material in a landfill site rather than a natural geological movement, said a statement on the Cabinet's website.

"Those held accountable will be seriously punished in accordance with the law," the statement said.

The disaster, which buried 33 buildings in an industrial park, has raised questions about China's industrial safety standards and lack of oversight that has led to fatal accidents, a by-product of the country's rapid growth.

There is still some risk of landslides at three places, and professionals have been brought in to deal with the issue, the Xinhua News Agency quoted a Shenzhen official as saying. "There are also dangerous chemical items that need to be identified and treated," said Yang Shengjun, head of the Shenzhen Housing and Urban-Rural Development Bureau.

Yang said no air or water contamination has been detected yet.

The company managing the dump site, Shenzhen Yixianglong, was urged to stop work four days before the disaster, an executive with a government-appointed monitoring agency said on Thursday.

Xinhua earlier reported that the dump was being used 10 months after it was supposed to have stopped taking waste, earning Yixianglong some 7.5 million yuan ($1.16 million) in fees.