Beijing |  The death toll from the collapse of an open pit coal mine in northern China has risen to four, with 49 people still missing, state broadcaster CCTV reported on Thursday.

Work had been suspended for several hours after an additional landslide at the gigantic facility following Wednesday's mine collapse in the vast Inner Mongolia region's Alxa League.

State media said the landslide struck at 6.00 pm Wednesday, about five hours after the initial cave-in of one of the pit's walls buried people and mining trucks below.

The official Xinhua News Agency said about 900 rescuers with heavy equipment were on the scene and work had resumed by Thursday morning.

Chinese President Xi Jinping has demanded "all-out efforts in search and rescue" and for "ensuring the safety of people's lives and property and maintaining overall social stability." Images of the collapse distributed by CCTV showed a massive wall of debris rushing down a slope onto people and vehicles below.

The company running the mine, Inner Mongolia Xinjing Coal Industry Co. Ltd., was cited and fined last year for multiple safety violations ranging from insecure access routes to the mining surface to unsafe storage of volatile materials and a lack of training for its safety overseers, according to the news website The Paper.

Inner Mongolia is a key region for mining of coal and various minerals and rare earths, which critics say has ravaged the original landscape of mountains, grassy steppes and deserts.

China overwhelmingly relies on coal for power generation but has tried to reduce the number of deadly mine accidents through a greater emphasis on safety and the closure of smaller operations that lacked necessary equipment.

Most mining deaths are attributed to explosions caused by the buildup of methane and coal dust, or to drownings caused when miners break into shafts that had been abandoned due to flooding.

China has recorded a slew of deadly industrial and construction accidents in recent months as a result of poor safety training and regulation, official corruption and a tendency to cut corners by companies seeking to make profits.

The economy has slowed, partly as a result of draconian lockdowns and quarantines imposed under the now-abandoned "zero COVID" policy.