Buenos Aires  - Argentine President Cristina Kirchner Sunday ordered an official period of mourning for Argentine folk singer Mercedes Sosa, who died Sunday in Buenos Aires after falling seriously ill with a liver ailment earlier in the week.

Kirchner and her husband, former president Nestor Kirchner (2003- 2007), joined cabinet members in an emotional farewell from the singer and national folk hero, whose body was held in state in Parliament.

Thousands of Argentinians filed past her open casket in the most formal room of Parliament, the "Pasos perdidos" room (the room of lost steps.) The steady stream of mourners continued well into the night as they passed by the artist, known fondly by her nickname of "Negra" (the black one.)

Several fellow artists including Teresa Parodi, Marian and Chango Farias Gomez, Suna Rocha, Angela Irene and Piero, tearfully sang some of her classics next to her coffin, such as Luna Tucumana, Al jardin de la republica, La anera and Si llega a ser tucumana - all of them songs made famous by Sosa.

One of the most emotional moments came as the leader of the organization, Grandmothers for Plaza de Mayo, Estela Carlotto, said her last goodbye. She stood as a representative for the 10,000 victims of the military dictatorship (1976-1983). Some of the grandmothers in the organization continue to search for the fate of their kidnapped children and grandchildren who were opponents of the regime. The musicians led those present in Sosa's song, "Valderrama."

Even the country's athletes paid tribute. All of the day's football games began with a quiet minute of remembrance.

"Mercedes was the most important voice and had a huge heart for all those who suffered," said the 32-year-old Colombia pop star Shakira in a statement. "She left us with remembrances of the sincerity of her performances as well as the light of her words and compassion."

Sosa is to be cremated on Monday. According to her wishes, the ashes are to be spread in her home province of Tucuman and in Mendoza Province, which she also favoured. The rest are to be buried at the Chacarita cemetery in Buenos Aires.

Mercedes Sosa became known around the world in the 1960s with songs such as Gracias a la vida, Cancion con todos and Alfonsina y el mar.

This year, she released a new double album Cantora, which was very successful in her home country. Cantora 1 was nominated for three Latin Grammy awards, including best album. (dpa)