Rescuers are still draining a flooded coal mine in north China's Inner Mongolia Autonomous Region Wednesday, hoping to rescue 31 trapped miners who have been in the pit for more than 50 hours.

Officials with the emergency rescue headquarters refused to speculate on the miners' survival chances.

Two pumps have been working at the site since Tuesday, draining about 435 cubic meters of flood water an hour, a spokesman with the emergency rescue headquarters said at a press briefing midday Wednesday.

By 11:00 AM Wednesday, 6,000 cubic meters of flood water had been pumped from the pit and the underground water level had stopped rising, said Wu Qingfeng.

He said two more powerful pumps, capable of pumping 1,000 cubic meters each, were being installed to speed up the drainage.

An estimated 100,000 cubic meters of water poured into the pit of Luotuoshan Coal Mine in Wuhai City, about 600 kilometers from the regional capital Hohhot, following a flood Monday morning.

Of the 77 people working in the pit, one is known to have died and 45 survived the accident so far.

Experts at the emergency rescue headquarters said the trapped miners were probably at two mining platforms, 189 meters and 289 meters underground.

A group of the People's Liberation Army (PLA) soldiers and excavators are drilling into the shaft and hope to reach at least one of the two locations Wednesday afternoon.

Most of the miners are migrants from Ningxia Hui Autonomous Region and the provinces of Shaanxi, Shanxi and Henan.

Dozens of anxious family members arrived at the site Wednesday, waiting for news.

Yang Jinxia, a peasant woman from Ningxia, said her brother, 39-year-old Yang Jinlin was among the 31 trapped.

"My husband and I accompanied my sister-in-law to Wuhai on Monday," she said. "She's in poor health and has two kids to tend -- so we let her go home and we stayed to wait for news."

The accident has aroused attention from the central government. Premier Wen Jiabao ordered "all-out rescue efforts" Monday night and Vice Premier Zhang Dejiang has arrived in Wuhai to oversee the rescue operation.

Luotuoshan Coal Mine is owned by Wuhai Energy Co. Ltd. and its parent company is Shenhua Group Corp. Ltd., one of China's leading mining firms.

Construction of the mine started in 2006. It is designed to produce 1.5 million tonnes of coal a year.

Last year, Inner Mongolia replaced northwest China's Shanxi Province to become China's leading coal base with 637 million tonnes of output, and reported 33 deaths in 21 mine accidents, a fatality rate of 0.052 per million tonnes, one of the lowest for China's major coal bases.

(Xinhua News Agency March 3, 2010)