Accident at Chinese mine kills 21

At least 21 people have died in an accident at a coal mine in China's northern Shanxi province.

State media says that seven miners managed to escape from the Wujiu mine and a further four were rescued.

An early investigation into the accident, which happened on Saturday, suggested that it had probably been caused by an explosion.

China's mines are among the deadliest in the world, with an average of ten miners killed every day in 2007.

Xinhua quoted an unnamed official as saying that all the victims died from carbon monoxide poisoning.

It said rescue work was continuing but it was not known how many miners had been underground when the accident occurred.

The Chinese government has taken measures to improve safety standards in recent years.

But the soaring demand for energy and widespread local corruption means that owners and operators often ignore safety measures in favour of increased production and greater profits.