RESCUERS battled dangerous levels of gas, tons of coal dust and the risk of falling rocks as they worked to free 16 miners trapped by an explosion at a mine in central China early yesterday. Twenty-one miners were confirmed killed.

The blast happened as the world still was celebrating Chile's dramaticrescue of 33 miners trapped for more than two months.

Rescuers have located the 16 Chinese miners but must clear tons of coal dust from the mine shaft to reach them, a rescuespokesman said. It wasn't clear if the miners were alive or how far underground they were trapped.

The blast unleashed more than 2,500 tons of coal dust, an engineer for one of the mine's parent companies, Du Bo, said. Ventilation has resumed in the mining pit but gas levels remain high.

The gas level inside the mine was 40 percent, far higher than the normal level of nearly 1 percent, China Central Television reported.

The gas wasn't specified, but methane is a common cause of mine blasts, and coal dust is explosive.

The more than 70 rescuers on the scene must also clear chunks of coal loosened by the blast that fell into the shaft, the TV report said.

The blast at the state-run Pingyu Coal & Electric Co Ltd mine happened as workers were drilling a hole to releasepressure from a gas buildup to decrease the risk of explosions, according to the work safety administration.

State media said another gas blast at the same mine two years ago killed 23 people.

The mine in the city of Yuzhou is a couple of hours outside the Henan provincial capital of Zhengzhou and about 690 kilometers south of Beijing.

China's mining industry is the most dangerous in the world, with 2,600 people killed in accidents last year and the country's leaders have been making a high-profile push in recent years to improve mine safety.

Mining fatalities decreased in recent years as China closed many illegal mines, but deaths increased in the first half of this year. At least 515 people were killed nationwide in coal mines alone.

• yesterday [´jestədi] n.&ad.昨天；前不久 (初中英语单词)
• dramatic [drə´mætik] a.戏剧的；戏剧般的 (初中英语单词)
• rescue [´reskju:] vt.&n.救援；挽救 (初中英语单词)
• normal [´nɔ:məl] a.正规的 n.正常状态 (初中英语单词)
• release [ri´li:s] vt&n.释放；放松；赦免 (初中英语单词)
• pressure [´preʃə] n.压榨 vt.对...施压力 (初中英语单词)
• decrease [di´kri:s, ´di:kri:s] v.&n.减少；减退 (初中英语单词)
• administration [əd,minis´treiʃən] n.管理(事务等)；经营 (初中英语单词)
• explosion [ik´spləuʒən] n.爆炸；爆发；发作 (高中英语单词)
• underground [,ʌndə´graund] ad.&a.地下(的) (高中英语单词)
• mining [´mainiŋ] n.采矿；矿业 (高中英语单词)
• explosive [ik´spləusiv] a.易爆炸的 n.炸药 (英语四级单词)
• provincial [prə´vinʃəl] a.省的 n.外省人 (英语四级单词)
• spokesman [´spəuksmən] n.发言人 (英语六级单词)
• ventilation [,venti´leiʃən] n.通风(设备)；换气 (英语六级单词)
• illegal [i´li:gəl] a.不合法的，非法的 (英语六级单词)