Volkswacht Bodensee - 17 dead in gas leak at South African slum

Emergency teams received a call at around 8:00 pm (1800 GMT) on Wednesday about a blast in the slum of Angelo, near the middle-class suburb of Boksburg.

They discovered a "leakage from a cylinder" containing a poisonous gas, emergency services spokesman William Ntladi said.

The leak is believed to have come from a cylinder of nitrate oxide, used in illegal mining activity in and around the settlement, he said.

Authorities gave a toll of around two dozen deaths on Wednesday night before revising it downward to 16.

Panyaza Lesufi, the premier of Gauteng province, said at the disaster site on Thursday that a 17th person had died after being taken to hospital.

"There are five others that were later admitted this morning. There is one under oxygen... Those in the hospital, the total number is 11," he told reporters.

- Devastation -

First responders found scores of people "lying all over the area, due to inhalation of this toxic gas", Ntladi said.

Rescue workers and forensic police combed through the affected area -- a cluster of squalid shacks built out of bricks and corrugated iron sheets -- late into the night, AFP journalists saw.

"I thought initially it was just an explosion in one area but... people were running away from the scene and then they started to fall -- they trying to get to areas were they can escape," Lesufi said.

Relatives of victims gathered in search of news.

"This morning when I woke to come here and check exactly what had happened, I found out that my sister is in hospital, she's been admitted, but my brother-in-law passed away," said Felsin Nyamuso.

Johannesburg, South Africa's commercial capital, is built around mountainous dumps of soil and cavernous pits left behind by generations of mining companies that first extracted gold in the 1880s.

Obsolete mines across South Africa attract scavengers known as "zama zamas" -- a word in Zulu which means "those who try their luck."

The work is often arduous and dangerous, but for many is the sole option in a country where a third of the workforce is unemployed.

Boksburg was last month struck by a 5.0 magnitude earthquake, suspected to have been linked to the maze of underground tunnels and shafts associated with illegal mining in the area.

- Call for clampdown -

South Africa's main opposition, the Democratic Alliance (DA), accused the government of failing to tackle the scourge.

"Illegal miners harm not only... residents but themselves," it said. "This illicit activity kills hundreds of them."

Samantha Hargreaves, director of the WoMin African Alliance, an NGO that campaigns against destructive mining, said mine closures and soaring unemployment had prompted many workers to turn to scavenging for gold.

"Informal mining is crime-based," she said. "These small alleged illegal miners you are seeing are part of massive national and international syndicates."

President Cyril Ramaphosa, in a statement, expressed his sympathies for the "devastating and tragic loss of innocent lives" and urged an investigation to "avoid similar disasters in future."

Boksburg was the scene of a massive gas tanker explosion that killed 41 people on Christmas Eve last year, after a truck carrying liquefied petroleum gas (LPG) got stuck under a bridge, triggering a leak and blast.

C.Kovalenko--BTB