Emergency crews are struggling to rescue 18 coal miners trapped underground in eastern China following a collapse inside the shaft three days earlier.
Three miners were killed by falling rocks in Saturday’s accident in Shandong province that also destroyed part of a drainage tunnel.
State media on Tuesday showed ambulances standing by at the mine entrance and crews equipped with oxygen tanks heading underground.
More than 300 people were working inside the mine at the time of the collapse, and most were successfully lifted to safety.
China long had the world’s deadliest coal mines but safety has improved considerably with more modern equipment, better training and the closure of most of the smallest, most dangerous mines. China relies heavily on coal for energy and heating.