Rescuers Friday sent food and messages of hope to miners who have been trapped for five days in a flooded north China coal mine.

The rescue team sent 360 bags of glucose, each 200 ml, down the 250-meter Wangjialing Coal Mine in Shanxi Province after hearing banging on a metal pipe.

A rescuer tears up a bag of glucose by his teeth at Wangjialing Coal Mine [Xinhua/Gao Xueyu] Click to see related Photo Gallery

Pan Zengwu, deputy chief of the Shanxi provincial coal geological bureau, said rescuers heard what they believed to be the trapped miners making the noise at 2:15 p.m..

The rescuers knocked on the drill pipe to respond, Pan said.

He said the rescue team sent 360 bags of glucose, each 200 ml, down the 250-meter pit.

Rescuers have been drilling holes to pump out water and send down food.

An iron wire was found attached at the end of a drill pipe when it was lifted to the surface at 3 p.m..

Pan said this was apparently tied on by the trapped miners.

Rescuers tried again to make contact with the miners by shouting through the pipe and knocking on the pipe at about 6:02 p.m. and 6:10 p.m. after they sent more bags of glucose down the pit.

After a period of silence, Xinhua reporters at the site clearly heard several sounds of tapping on the pipe from underground.

"It is a good news. So long as they are still alive, it is all worth it for us to work even harder," said a rescuer surnamed Liu from central Henan Province.

With glucose, rescuers sent a plastic bottle containing two short letters, a ballpoint pen and paper down the pit. They also sent down a special phone for use in mines.

One letter said: "Dear fellow workers, the Party Central Committee, the State Council and the whole nation have been concerned for your safety all the time... All of us are very happy about the message of life you have conveyed, and are racing the clock and going all out to save you. You must have confidence and hold on to the last!"

The other said: "Dear brothers, please wait in patience... The water will be soon drained. You must hold on and on! How about the gas and ventilation underground? What do you need us to do? Please tell us..."

About 3,000 rescuers are struggling to pump water and reach the trapped miners.

The water level underground had dropped by 3.3 meters by 4 p.m. Friday after a total of 66,000 cubic meters of water had been pumped from the shaft, said Liu Dezheng, a spokesman of the rescue headquarters and deputy director of the General Office with the Shanxi Provincial Work Safety Committee, at a news conference late Friday.

Altogether 14 pumps were pumping up to 1,935 cubic meters of water per hour, he said, adding rescuers were installing one more pump.

Rescuers said the trapped miners were working on nine different platforms, and four platforms had not been totally submerged, making it possible that some workers could have survived.

The flooding happened at about 1:40 p.m. Sunday when underground water gushed into the pit of Wangjialing Coal Mine, which was under construction. Altogether 261 miners were working underground, and 108 were lifted safely to the surface.

Rescuers said the flooding took place when workers digging tunnels broke through into an old shaft filled with water.

The mine, which straddles Xiangning County, of Linfen City, and Hejin, a county-level city within Yuncheng City, covers about 180 square kilometers.

The mining zone was estimated to have more than 2.3 billion tonnes of coal reserves, including 1.04 billion tonnes of proven reserves, according to the company's official website.

The mine, affiliated to the state-owned Huajin Coking Coal Co. Ltd., is a major project approved by the provincial government. It is expected to produce 6 million tonnes of coal annually once in operation.

If the trapped workers cannot be saved, the accident will be China's worst mining disaster in more than two years. In August 2007, a total of 181 workers died at two flooded coal mines neighboring each other -- 172 at one mine -- in Xintai, eastern Shandong Province.