State television showed the rescue officials laying flowers and observing a minute's silence at the site where mud to the height of a five story building engulfed an area bigger than 10 football fields.
An official investigation determined that the landslide which killed at least four people was a man made tragedy and not a geological disaster.
The tragedy was caused by the collapse of a huge pile of construction waste, rather than any natural geological phenomenon, the probe report said.
Ma said Shenzhen will actively cooperate with the investigation.
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Yang Shengjun, head of the Shenzhen Housing and Urban-Rural Development Bureau, said that there was still "some risk" of more landslides at three separate locations in the industrial park, and that they have dispatched professionals to deal with it.
"There are also dangerous chemical items that need to be identified and treated," Yang said, adding that no air or water contamination has been detected since the disaster, state-run Xinhua news agency reported.
The landslide has also affected more than 4,600 workers in 90 factories and workshops, including 34 plants which were buried or damaged by mud and waste.
A nearby section of the West-to-East natural gas pipeline exploded after the landslide struck the Hengtaiyu industrial park on December 20, causing more than 100,000 square meters of debris.
An official company of a dumpsite was blamed for the disaster andone of its official has been detained for questioning.