The headquarters demanded an increase in the number of workers installing the large pumps and operating small and medium-sized ones for continuous drainage operations.

As more rescue workers arrived in the shaft, the number of people working in the mine's canteen doubled. At the peak of the rescue work, they supplied more than 1,000 meal boxes a day to those underground, up from several hundred typically.

Shen Hualin, deputy secretary-general of the Yibin municipal government, said the loss of power badly hampered efforts to find and rescue those who were trapped.

During the rescue operations, 45 vehicles providing emergency power were at the site to ensure there were no blackouts.

At 2:55 am on Wednesday, thunderous applause and cheers broke the silence of the night at the rescue headquarters.

Some 10 minutes earlier, workers had arrived at an area close to where the miners were trapped. Suddenly, they saw Liu Guihua swimming toward them.

He was weak but also excited, and it took him some time to tell the rescuers that another 12 miners were trapped.

Liu Guihua has worked at the mine for 36 years. He said that when he and his 12 colleagues started work on Dec 14, each had a boxed meal with them.

"We finished the meals that day, and in the days to come, we ate mud, leather belts and coal and drank water leaking from the roof," he said.

"When it was at its highest level, the water flooding the mine was still 7 or 8 meters away from our feet. I did not sleep much and kept observing the water level. If it had continued to rise, we would have perished," he said.