Eleven people have been arrested in China for their role in a massive landslide that left some 12 people dead and over 60 others missing in a southern town.

The arrests were made in the southern city of Shenzhen, with Chinese prosecutors blaming breaches of construction safety rules for the tragedy last month. 

On December 20, heavy rains caused a construction waste dump piled up against a hill to collapse.

The landslide, which hit the Hengtaiyu Industrial Park in Shenzhen, buried 33 buildings, including three dormitories. Some 62 people are still missing and presumed dead, according to reports.

Chinese authorities said last week the landslide was an industrial accident and not a geological disaster.

Among the detainees are a legal representative and a deputy general manager of Shenzhen Yixianglong Investment Development, the company running the landfill, and other officials in charge of supervising it.

Those arrested were charged with criminal negligence, with prosecutors asking police to track down other suspects.

The Ministry of Land and Resources has said the disaster was caused by improper storage of waste from construction sites.

According to reports, soil was illegally piled 100 meters (330 feet) high at an old quarry site and turned to mud during rain.

Official documents show authorities were aware of problems with the soil storage and had urged action as early as July.

In November, a similar slide claimed the lives of 38 people in China’s eastern province of Zhejiang.