Beyoncé and other stars to perform at Nelson Mandela festival

Beyoncé and other international stars have gathered in South Africa for a charity concert honouring Nelson Mandela, a century after he was born.

Pharrell Williams, Trevor Noah and Oprah Winfrey were among those headlining the Global Citizen Festival: Mandela 100 at Johannesburg's FNB Stadium on Sunday. Model Naomi Campbell and singer Bob Geldof, who organized the Live Aid concerts for Africa, are also attending.

Sunday's concert is part of events marking the 100th anniversary of the birth of the anti-apartheid leader and Nobel Peace Prize winner, organizers have said. Winfrey will give a keynote address on the legacy of Mandela, South Africa's first black president.

Global Citizen, an advocacy group, campaigns against poverty and other causes. It says many people won tickets to Sunday's concert through charity work and petition-signing.

Others headlining the festival include Ed Sheeran, Usher and African artists including Wizkid, Cassper Nyovest and Femi Kuti.

South African media say a concert worker died in a stadium fall Saturday. It's the same stadium where world leaders gathered for a memorial after the death of Mandela in 2013.

The Global Citizen movement has a goal of ending extreme poverty by 2030, and its Mandela 100 campaign hopes to bring in $1 billion US in new pledges for the world's poorest people.

Canadian Prime Minister Justin Trudeau tweeted to Noah Sunday that he couldn't attend but that Canada is pledging $50 million to support education for women and girls around the world.

The PMO later clarified that the funding comes from the announcement earlier this year at the Quebec City G7 summit that Canada has raised more than $3.8 billion in an effort with other countries to send the world's poorest girls to school.