Police in northern China have detained seven people thought to have been involved in an attempt to cover up an accident at a gold mine last month.

In the beginning (local officials) were really unwilling to help, even after we made significant discoveries like the dumped bodies

Chu Gang, investigator

After the blast at the mine in Shanxi province, in which nearly 40 people died, many of the bodies were dumped at various locations several kilometres away.

Investigators said the four main suspects, including the owners and a foreman of the mine in Yixingzhai, were still at large.

A local newspaper said the miners died after being ordered to keep working even though a fire was raging around them.

The electrical fire was then reported to have detonated the tonnes of explosives stored in the mine.

Officials 'unhelpful'

A judge helping with the investigation, Chu Gang, said that initially local police and officials had been unwilling to co-operate in the inquiry.

China's huge mining industry has a poor safety record with more than 3,000 deaths reported in the past six months alone.

China has recently ordered illegal mines to close, but this is not in the interests of the local authorities, who rely on the mines' revenue.

Analysts say that the government's pledge to jail the officials responsible for poor safety may actually lead to more accidents going unreported.

More than 12,000 mines have closed because of safety concerns since last May.

The new closures will leave China with about 15,000 mines, down from 82,000 in 1997.