Forensic experts in South Africa are trying to determine what caused the deaths of 22 young people in a nightclub in the city of East London.
Police have ruled out a crush and say the party-goers may have ingested a toxic substance.
Most of the dead were teenagers as some are reported to have been celebrating the end of their exams.
Local officials said they feared it was a case of under-age drinking gone wrong.
President Cyril Ramaphosa expressed his condolences, and said he was concerned that young people had gathered at a venue that should be off-limits to under-18s.
