Zindzi Mandela, the daughter of South African anti-apartheid leaders Nelson Mandela and Winnie Madikizela-Mandela, has died aged 59.

Nelson Mandela’s daughter, Zindzi dies at 59.

State television South African Broadcasting Corporation has reported that Mandela died at a Johannesburg hospital early Monday morning.

She was the South African ambassador to Denmark at the time of her death. The cause of her death was not immediately revealed.

“The 59-year-old daughter of former president Nelson Mandela and struggle stalwart Winnie Madikizela-Mandela, passed away at a Johannesburg hospital in the early hours of this morning,” said SABC.

She was Nelson Mandela’s sixth child and his second with Winnie Madikizela-Mandela.