Johannesburg, Oct 28 (IANS): A toxicology investigation confirmed the recent deaths of six children in Soweto were caused by ingesting a dangerous organophosphate pesticide, South African authorities announced on Monday.

"All the six children died of Terbufos ingestion. In the past weeks, several chemicals were bandied around as possible causes of death. Some were even found in some retailers," Health Minister Aaron Motsoaledi said at a press briefing.

He further explained that organophosphate is not one substance, but a group of substances typically used in agriculture or as pesticides.

The announcement came after 80 environmental health practitioners were deployed in Soweto last week to investigate the deaths of six children, aged between six and nine, who died on Oct. 6 after allegedly "buying snacks" from a tuck shop.

Motsoaledi noted that four people were arrested at a Johannesburg mall after being found trading in a chemical called aldicarb, which falls in the class of carbamate, with 1,450 grams of the substance seized. While aldicarb was not the cause of the children's deaths, it could not be sold publicly.

He further clarified that carbamate is another group of chemicals used as pesticides, adding that there is a "slight difference" between carbamate and organophosphate. "One major difference is that organophosphate is much more lethal and can cause irreversible damage," he said.

According to Motsoaledi, some tuck shop owners confessed to the department that the four arrested were the ones supplying them with illegal pesticides.

"The samples that were taken via swaps in the various spaza shops in Soweto have been sent to the National Health Laboratory Service and we are still waiting for the results," the minister said, Xinhua news agency reported.

While organophosphate was detected in the bodies of the children, Motsoaledi revealed that the department was still awaiting results to check "if the same organophosphate was found in the spaza shops."