Students have died as a result of suspected energy drink poisoning.

Three of a father's boys, aged six, thirteen, and sixteen, died after consuming an energy drink that he reportedly provided them, according to South African authorities.

Two of the siblings passed away at school, while the third passed away on the way to the hospital.

A fourth youngster who drank the drink is in severe condition at a local hospital, according to reports. The energy drink was not consumed by a fifth brother, who is fine.

"A case of murder has been opened with three charges, as well as a case of attempted murder," said Brig Brenda Muridili, a police spokesperson.

After allegedly attempting to poison himself, the father is reportedly being guarded in hospital.

The education administration in Gauteng province issued a statement expressing sorrow over the deaths of the three siblings at Ratanda Primary and Khanya Lesedi Secondary Schools.

When asked if the deaths were caused by pollution or poisoning, Panyaza Lesufi, a county education administrator, called it "a planned act."

"It appears to have been an intentional act, as the father also tried suicide, according to the information we have. It's a sign that this was all planned out ahead of time "He told eNCA, a local television network.

"We've also received unsubstantiated claims that the mother is in the hospital, but we need to double-check that."

On Friday, they will visit the schools and families, according to the official.

A psychosocial support unit has been dispatched to the bereaved family and the school community to provide counseling.