The Indian nun who replaced Mother Theresa as head of the Missionaries of Charity has died. She was 81.

The charity said Sister Nirmala Joshi's health had been declining in recent days, but did not give any more details about the cause of her death early Tuesday.

She was selected to lead the charity six months before the death of its founder, Mother Theresa, in 1997. She carried out the role until stepping down in 2009.

Indian politicians including Prime Minister Narendra Modi and opposition Congress party leader Sonia Gandhi praised her work for the poor in the eastern city of Kolkata, where the charity is based.

West Bengal's highest elected official, Chief Minister Mamata Banerjee, said in a Twitter message that "Kolkata and the world will miss her."