Nuns perform a special prayer next to the tomb of Mother Teresa in Kolkata, India, on Tuesday after Pope Francis set Sept. 4 for her canonization. (AFP/Getty Images)

Nuns with the missionary order of the late Mother Teresa joined in hymns and offered special prayers on Tuesday after Pope Francis announced that the famed caregiver who worked in the slums of India will be elevated to sainthood in September.

“We are very happy,” Sunita Kumar, a longtime friend of Teresa’s, told reporters shortly after the Vatican announcement of the Sept. 4 canonization.

Members of Teresa’s Missionaries of Charity broke into prayerful celebration in Kolkata, formerly known as Calcutta, which she adopted as her home for more than four decades and where she served the homeless and the desperately poor.

The canonization will take place at the Vatican, a day before the 19th anniversary of her death. But Kolkata has already started preparing with church-organized events for the woman known as the “saint of the gutters.”

Mother Teresa’s portrait is shown beside her tomb in Kolkata, India, on Tuesday. (Bikas Das/AP)

The announcement “not only has brought smiles on our faces but also has given us another reason to live and bring meaning to our lives and the lives of others,” said Archbishop Thomas D’Souza, who celebrated a special Mass. “Because Mother, as an icon of mercy, of service of God’s love and his presence among the poorest of poor, continues to give meaning to the lives of everyone.”

Teresa, born Agnes Gonxha Bojaxhiu in 1910 in what is now Skopje, Macedonia, joined the Loreto order of nuns in 1928 and said she was inspired to found the Missionaries of Charity while on a trip to India in 1946.

The order has more than 130 centers around the world. The nuns are recognizable by their signature plain-white cotton sari with a blue border.

Pope John Paul II beatified Teresa in 2003, the first step toward possible sainthood. In December, the Vatican announced that Teresa’s intervention in healing a Brazilian man suffering from a viral brain infection in 2008 had been declared miraculous — “inexplicable in the light of present-day medical knowledge.”

Even though she is beloved by many Indians, Teresa’s work has drawn criticism from some groups in India.

Last year, Mohan Bhagwat, the head of India’s largest Hindu nationalist organization, the Rashtriya Swayamsevak Sangh, accused her of an “ulterior motive” — converting Indians to Christianity.

“In the name of service, religious conversions were made,” Bhagwat said. Five Indian states have laws against forced religious conversions, but there is no national law. In the 1970s, Teresa had opposed a proposal to enact such a national law.

Christians make up 2.3 percent of the 1.2 billion people in India, an officially secular but predominantly Hindu nation.

Last year, orphanages run by Teresa’s nuns shut down their adoption services because they did not want to comply with a new government system that makes it easier for single and divorced people to adopt.

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