Rome, Johannesburg - Tributes began pouring in Monday for South African singer and anti-apartheid icon, Miriam Makeba, who died Sunday from a heart attack in an Italian clinic.

Makeba, 76, collapsed shortly after a performance on Sunday evening and was brought by ambulance to a hospital in Castel Volturno in southern Italy, where she died, a hospital director said.

"She arrived at the Pineta Grande hospital at around 11:15 on Sunday night. By then her heart had stopped beating and all attempts to revive her were unsuccessful," the director, Francesco Longanella, told Deutsche Presse-Agentur dpa.

The singer had taken part in a concert to support Italian writer Roberto Saviano's campaign against the Camorra, the local version of the Mafia that centres its criminal activities in and around Naples, including Caste Volturno.

Makeba's performance was also meant to pay homage to six African immigrants gunned down in a suspected Camorra killing in Castel Volturno in September.

"Miriam Makeba will always be part of our community," Castel Volturno Mayor Francesco Nuzzo said in his tribute to the South African singer.

Nuzzo, who, like Saviano, has received death threats from the Camorra, said Makeba, despite recent poor health, had wanted to show solidarity with the people of Castel Volturno which is home to many African immigrants.

"She was an inspiration for all black people around the world," said Congo-born Italian parliamentarian, Jean Leonard Touadi, who recalled Makeba's activism against racial segregation in South Africa.

South African Ambassador to Italy, Lenin Shope, together with relatives of Makeba were expected later Monday at the hospital, Longanella told dpa.

Makeba, was born on March 4, 1932, and enjoyed international fame with the hit song Pata Pata.

Known as Mama Africa, Makeba also worked as an actress, author and composer and received awards several awards for her fight against apartheid in South Africa.

The artist, who matured in the Johannesburg jazz scene of the 1950s, was one of the first who brought her continent's music to the West in the following decade.

Forced to live in exile for 30 years because of her political activities first in Britain and later in the United States and Guinea, she was only allowed to return to South Africa in 1990. (dpa)