WORKERS trying to find 47 people missing after a collapse at an open-pit mine in northern China have had to change their excavation methods to avoid causing more landslides, state media reported today.

Six people have been confirmed dead and six injured have been rescued at the mine in Alxa League, an administrative division of Inner Mongolia, as of Thursday night, according to broadcaster CCTV.

With a large collapsed area at the mine, the digging done by backhoes and bulldozers can risk more collapses.

The crews are excavating by layers and making trapezoid-shaped descents to carry on their search from both sides of the mountain in an adjustment of their rescue plans, the report said.

“It is very challenging to conduct rescue work,” said Alxa League head Li Zhongzeng.

“Rescuers from everywhere, including neighbouring regions, are rushing to the site.”

The initial cave-in of one of the pit’s walls occurred at about 1pm on Wednesday, burying people and mining lorries under tons of rock and sand.

Another landslide about five hours later halted rescue efforts before they resumed on Thursday.

Chinese President Xi Jinping has called for an “all-out” search-and-rescue effort.