Anxious relatives demanded access to a coal mine Monday after an explosion killed at least 138 miners and left 11 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 recovering from a toxic spill in a river that forced the government to cut off water supplies for five days.

Outside the mine, located in Heilongjiang province in northeastern China, black government sedans and emergency vehicles made their way along 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. When the guards refused, the women shouted obscenities at the men.

The disaster was 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.

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 are not expected to reopen.

Government officials attributed the explosion in Qitaihe to airborne coal dust that ignited. But there was no word on whether they believed misconduct or human error were involved.

Rescuers had found 74 miners alive by Monday and were continuing to search, the official New China News Agency said.

Government television 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," one miner said as he lay on a stretcher.

The provincial governor, Zhang Zuoji, was shown visiting survivors in a local hospital. Most wore oxygen masks, and many lay in bed still in their work clothes, their faces caked with black grime.