There are 16 confirmed deaths, the other victims were revived by paramedics and taken to hospitals, emergency services spokesman William Ntladi told AFP. Four of the injured were in mortal danger, the condition of eleven other injured was "serious but stable". Five women and three children were among the dead.
The rescue service was alerted around 8:00 p.m., initially because of a suspected explosion. The rescue workers then found a gas leak. A cylinder with a "poisonous gas" was found on site. Initial investigations indicated that the gas had been used for "illegal mining activities," he added.
With an unemployment rate of over 32 percent, thousands of people work in illegal mining in South Africa. They are called "Zama Zamas", which means "those who try their luck" in Zulu. They prospect for gold unofficially and under harsh and often dangerous conditions in old mines.