Five coal mine bosses have been jailed for up to life for a coal mine blast that killed 26 people in northern China in March, a state news agency said Tuesday.

Xinhua News Agency said Zhou Xiaogen, former owner of the Yujialing Coal Mine in Linfen, a city in Shanxi province, was sentenced to 20 years in prison by the Linfen Intermediate People's Court.

It said Zhou operated the mine without license. He was also fined 3 million yuan (US$394,000).

Zhou Linggen, the mine's general manager, was sentenced to life. The court said he had used substandard explosives bought from unauthorized sources.

Three other managers were given jail terms of five to eight years.

Xinhua said the mine bosses had been ordered to close the mine several times in the month before the blast.

Seven local Communist Party and government officials were removed from their posts after the accident, it said.

China's coal mines are the world's deadliest, with numerous fires, floods and other disasters every year despite repeated government promises to improve safety.

The government says 4,750 people died in coal mine accidents last year _ an average of 13 a day. It is common for mine owners to delay reporting accidents or to not report them at all.