At least 21 teenagers, including a 13-year-old, mysteriously died in a nightclub in South Africa on Saturday.
Many are thought to have been students celebrating the end of their high-school exams on Saturday night, provincial officials said.
There were no visible wounds on the bodies. Officials have ruled out a stampede as a possible cause and said autopsies would determine if the deaths could be linked to the poisoning.
Crowds, including parents whose children were missing, gathered on Sunday outside the tavern where the tragedy happened in the city of East London, while mortuary vehicles collected the bodies, an Agence France-Presse (AFP) correspondent saw.
Senior government officials rushed to the southern city, including national Police Minister Bheki Cele, who broke down in tears after emerging from a morgue where the bodies were being kept.
"It's a terrible scene," he told reporters. "They are pretty young. When you are told they are 13 years, 14 years and you go there and you see them. It breaks (you)."
The provincial government of Eastern Cape said eight girls and 13 boys had died. Seventeen were found dead inside the tavern. The rest died in hospital.
Drinking is permitted for over-18s in township taverns, commonly known as shebeens, which are often situated cheek by jowl with family homes or, in some cases, inside the homes themselves.
But safety regulations and drinking-age laws are not always enforced.
"We have a child that was there, who passed away on the scene," said the parents of a 17-year-old boy.
"This child, we were not thinking was going to die this way. This was a humble child, respectful," said grieving mother Ntombizonke Mgangala, standing next to her husband outside the morgue.
President Cyril Ramaphosa, who is attending the G-7 summit in Germany, sent his condolences.
He voiced concern "about the reported circumstances under which 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."
The authorities are now considering whether to revise liquor licensing regulations. South Africa is among the countries in Africa where most alcohol is consumed.
"It's absolutely unbelievable ... losing 20 young lives just like that," Provincial Prime Minister Oscar Mabuyane said, visibly shocked.
He was speaking to reporters before the toll was updated to at least 21. He condemned the "unlimited consumption of liquor."
"You can't just trade in the middle of society like this and think that young people are not going to experiment," he said from outside the tavern, in a residential area called Scenery Park.
Empty bottles of alcohol, wigs and even a pastel purple "Happy Birthday" sash were found strewn on the dusty street outside the double-story Enyobeni Tavern, according to Unathi Binqose, a safety government official who arrived at the scene at dawn.
Ruling out a stampede as the cause of death, Binqose told AFP: "There are no visible open wounds."
"Forensic (investigators) will take samples and test to see if there was any poisoning of any sort," he said, adding the bar was overcrowded.
Local newspaper DispatchLive reported on its website: "Bodies are lying strewn across tables, chairs and on the floor, with no obvious signs of injury."
Parents and officials said they understood many of the dead were students celebrating "pens down" parties held after the end of high school exams.
Local television showed police officers trying to calm down a crowd of parents and onlookers gathered outside the club in the city, which is located on the Indian Ocean coast, nearly 1,000 kilometers (620 miles) south of Johannesburg.
