BEIJING — Coal dust caught fire in a mine in northeast China, sparking an explosion that killed at least 68 people and left 79 missing, the government said today, as the country's leadership called for tighter work safety measures.

Some 221 miners were underground when the blast occurred late Sunday at the Dongfeng Coal mine in Qitaihe, a city in Heilongjiang province, the official Xinhua News Agency said.

Seventy-four miners had been rescued, it said.

Xinhua said a 269-member rescue team was searching for the trapped miners and that Li Yizhong, minister of the State Administration of Work Safety, told them to "spare no efforts" to save the workers.

China's coal mines are the world's deadliest. Fires, floods, cave-ins and explosions are reported almost daily, and thousands of miners are killed every year despite the government's repeated attempts to improve its record amid lax safety rules and poor equipment.

Efforts to shut down dangerous mines have been complicated by the country's soaring demands for power to drive its booming economy.

HARBIN, China — Five days after an embarrassing chemical spill, China's government celebrated the return of running water to this city of 3.8 million as a victory for the communist system while warning the water was still not safe to drink.The spill was a political disaster for President Hu Jintao's government and cast a harsh light on the environmental costs of China's breakneck development.Hu's government issued apologies to China's public and to Russia, where a border city downstream is bracing for the arrival of the 50-mile-long benzene slick.State media have accused officials of lying about and trying to conceal the spill — the result of a Nov. 13 chemical plant blast in Jilin, a city upstream from Harbin, that killed five people and forced 10,000 more to flee their homes.By The Associated Press