South Africa gas leak death toll rises to 17

The death toll from a toxic gas leak linked to illegal mining has risen to 17, including three children.

The deaths occurred on Wednesday in the informal settlement of Angelo in Boksburg, on Johannesburg's eastern outskirts.

Authorities believe the toxic nitrate gas came from canisters kept in shacks within the settlement, used by illegal gold miners who use the gas to separate gold from rock and dirt. 

In addition to the 17 deaths, 10 people were hospitalised, including a two-month-old baby, two 4 year-olds and a 9 year-old, according to officials. The three children who died were aged 1, 6 and 15. 

Police on Thursday began the task of finding evidence and removing remaining gas canisters they found. 

Widespread illegal mining

Wednesday's incident is not a stand-alone one, with fatalities linked to illegal mining all too common. 

There are thousands of illegal miners in South Africa, many of whom are from neighbouring countries such as Lesotho. 

The miners go in search of precious metals, stones and even coal in mines long closed off because they are no longer deemed profitable. 

In late June, at least 31 illegal miners were found dead due to a gas explosion in an abandoned mine in Welkom, 250 km south of Johannesburg.