Methane can be controlled and the explosion is the result of negligence

Mineworkers' spokesman

The National Union of Mineworkers was speaking the day after a mining accident that left 12 people dead.

The accident happened almost exactly a year after a similar one at the same mine that killed seven miners.

Gold Fields who have not respondend to the negligence claims, have said that all the recommendations arising from an investigation into the earlier accident had been implemented.

The accident at the Beatrix mine near Welkom, 280km (175 miles) south-west of Johannesburg was the country's worst for two years.

A rescue team was sent down the mine

Kevin Barnes, senior human resources manager for the company, said that the cause of the accident was not immediately clear.

Mr Barnes told the BBC that "there seemed to be a pocket of methane in the area where the accident happened" due to the breakdown of an underground fan.

He suggested that this could be the cause.

Dangerous profession

NUM spokesman Moferefere Lekorotsoana said: "Methane can be controlled and the explosion is the result of negligence."

He told AFP that the company did not take worker safety seriously.

Mr Barnes said that this was not the case and "the whole management team was in mourning" over the accident.

A spokesman for South African Minerals and Energy Minister Phumzile Mlambo-Ngcuka said there would be an investigation into the explosion.

More than 300 South African miners were killed in deep mining incidents in 1999, including 19 in one explosion in July of that year.

Methane, a colourless and odourless gas, was the cause of that blast.

But the industry's safety record has improved in recent years owing to better equipment and training.