Updated

Anxious relatives demanded to be allowed into a coal mine Monday after an explosion killed at least 134 miners and left 15 others missing, adding to a soaring death toll in China's mines despite a safety crackdown.

The blast in the Dongfeng Coal Mine prompted national leaders to demand stricter enforcement of safety rules in China's mining industry, by far the world's deadliest, with more than 5,000 fatalities a year in fires, floods and other accidents.

The disaster late Sunday came as the nearby city of Harbin was struggling to recover from a toxic spill in a river that forced the government to cut off water supplies for five days.

Outside the Qitaihe mine in China's northeast, a stream of emergency vehicles with flashing red lights and black government sedans made their way up and down the narrow, two-lane road to the mine entrance.

Security guards blocked the front gate as about a dozen people stood outside in subfreezing weather and a nighttime fog. Four women argued loudly with the guards, demanding to be let in to look for missing relatives.

"Why won't you let us in?" one shouted. When the guards refused, the women shouted obscenities at the men.

People who answered the phone at the mine office said they were too busy to give any information.

The disaster is a setback for Chinese officials struggling to improve safety in the coal mining industry. Most accidents are blamed on disregard of safety rules or lack of equipment for ventilation or fire control. Local officials often are accused of helping mine owners or managers flout safety rules.

Beijing has unveiled one safety initiative after another in recent years. It has announced the creation of a national network of safety inspectors, stricter fire standards and shorter working hours for miners to prevent fatigue.

Authorities say they have shut down more than 12,000 coal mines this year for safety inspections. Thousands have been ordered to improve their facilities and many others aren't expected to reopen.

The government said the explosion in Qitaihe was blamed on airborne coal dust that ignited. But there was no word on whether it was believed to involve misconduct or human error.

Rescuers had found 74 miners alive by Monday, the official Xinhua News Agency said.

It said 134 miners died in the explosion and a team of 269 rescuers was searching for 15 others, but gave no indication whether they were believed to be alive.

Government television in Heilongjiang province, where Qitaihe is located, showed an injured miner, his face black with coal dust, being led from the mine and collapsing onto a stretcher. Rescuers in orange jumpsuits and respirators were shown descending into the pit.

"We couldn't breathe," said one miner as he lay on a stretcher.

Provincial Gov. Zhang Zuoji was shown visiting survivors in the hospital. Most wore oxygen masks and many lay in bed still in their work clothes, their faces caked with black grime.

Zhang rushed to Qitaihe from Harbin, about 250 miles to the west, where he had just taken part in festivities marking the restoration of running water that was suspended after a spill of toxic benzene in the Songhua River.

The string of disasters has embarrassed the government of President Hu Jintao, which has promised to improve the lives of the poor majority who have been left behind by China's 25-year-old economic boom.

Following the latest blast, Hu and Premier Wen Jiabao urged officials to curb the "possible occurrence of big safety accidents which claim huge casualties," the state newspaper China Daily said.

It said they demanded stricter inspections and punishments for violators.

But efforts to close dangerous coal mines have been complicated by China's soaring demands for power to feed its booming economy. The loss of mining jobs is especially painful in a region like the northeast, where state companies are laying off millions of workers in a struggle to compete in the new market-oriented economy.

Coal mining is a key industry in Qitaihe, a town at China's far northeastern edge, near the Russian border. Towering piles of waste rock from dozens of pits dot the landscape.

Also Monday, 18 miners missing in another coal mine disaster in the northern province of Hebei were confirmed dead following an underground flood last week, Xinhua said. The mine owners fled after the flood, complicating search efforts, the agency said.