“Others would just feel dizzy, sleep on the sofa, (and) die. It tells you the story that they were all kids because somebody should have taken note.”

Speculation has swirled over the cause of the tragedy, starting with a stampede – that has now been ruled out – to a possible gas leak. Police have sent forensic samples from the victims to a toxicology laboratory to investigate if the teens ingested poison or a toxin at the party.

Police said they were called to the Enyobeni Tavern in the city of East London in Eastern Cape province at around 4am on Sunday after receiving a report that there were “lifeless bodies” there.

Officers responding to the call walked in on a grim scene: 17 of the teenagers were found dead in the nightclub. Two more died at a local clinic, one died on the way to another hospital and one at that hospital. Their ages were between 13 and 17, police said.

Police spokeswoman Colonel Athlenda Mathe said an investigation was ongoing and no cause of death had yet been established.

But Cele said forensic samples were being sent to an advanced toxicology laboratory in Cape Town, indicating that police were looking at the possibility that poison or a toxin was involved. Cele said the toxicology tests might take “a lot of time”.

Provincial safety official Unathi Binqose told the Daily Maverick newspaper that the victims may have ingested a toxic substance through alcohol they were drinking or through hookah pipes, which were being smoked at the party.

Initial reports speculated that the victims – 12 boys and nine girls – may have died in a crush because of overcrowding at the party, but authorities found no visible signs of injuries on the bodies and police have now ruled that out.

The teenagers were reportedly celebrating the end of midyear exams, a local DJ’s birthday and the relaxing of some of the last Covid-19 restrictions in South Africa, which was announced earlier in the week.

Parents were asked to come to a mortuary to identify their children. The Eastern Cape health department said there were survivors being treated in the hospital for backache, tight chests, vomiting and headaches.

Sinovuyo Monyane, 19, who was hired by the bar to promote an alcohol brand, said she was still “confused” but felt lucky to be alive.

She said she struggled to escape through a door gridlocked with people.

“We tried moving through the crowd, shouting ‘please let us through’, and others were shouting ‘we are dying, guys’ and ‘we are suffocating’ and ‘there are people who can’t breathe’,” she told Agence France-Presse.

“I passed out at that moment. I was running out of breath and there was a strong smell of some type of spray on in the air. We thought it was pepper spray,” she said.

She later regained consciousness after someone sprayed water on her.

“I got up and realised that there were bodies lying around. I saw people being poured water, but those people did not even move,” she said in a phone interview.

“I could have died.”

A member of staff at the bar, Sifiso Promise Matinise, said he sprinkled water on the unconscious people to revive them, thinking they were drunk, before realising what had happened.

“I saw two people collapse, they died,” he said.

South African President Cyril Ramaphosa, who is in Germany for the G7 summit, offered condolences to the families of the victims in a statement, but also said he was concerned why “such young people were gathered at a venue which, on the face of it, should be off limits to persons under the age of 18”.

It’s illegal for anyone under 18 to consume or buy alcohol in South Africa and the Eastern Cape Liquor Board said it was revoking the nightclub’s liquor license and would pursue criminal charges against the club’s license holder.

The tragedy will put renewed scrutiny on the many bars and nightclubs operating in the backstreets of poor neighbourhoods in South Africa and which are often criticised for not abiding by liquor laws.

Associated Press and Agence France-Presse