New Delhi - Prayers were held to mark Mother Teresa's 99th birth anniversary Wednesday at the headquarters of the religious order she founded, the Missionaries of Charity.

A Mass was also organized at the headquarters in India's eastern city of Kolkata, where visitors joined nuns for the service, said Sister Christie, spokeswoman for the congregation.

"After the Mass, the mother's tomb was opened to visitors," she said. "People prayed, lit candles and laid flowers. The prayers were also held at most of our branches worldwide."

Sister Mary Prema, who now heads the Missionaries of Charity, said everyone prayed and remembered Mother Teresa for dedicating her life in the service of the poor.

"Mother Teresa opened her heart to love all people," Sister Prema told the gathering in Kolkata. "She continues to inspire us all to open our eyes to see the dignity of a child of God in the poor and to bring peace and joy to them through our humble services."

The Missionaries of Charity also launched a year of programmes to celebrate the birth centenary of their founder.

"Our sincere endeavour to be channels of God's love and peace to the poor will be the best gift we all can prepare for mother's 100th birthday," Sister Prema said.

Mother Teresa, an ethnic Albanian, lived and worked in Kolkata for more than 45 years ministering to the sick, dying and orphans.

She founded the Missionaries of Charity in 1950. Teresa came to India in 1929 and took up teaching and became an Indian citizen in 1948.

The Nobel Peace Prize winner was beatified by Pope John Paul II and given the title Blessed Teresa of Kolkata in 2003.

Mother Teresa, who was popularly known as the "Saint of the Gutter" died at the age of 87 on September 5, 1997.

The Missionaries of Charity now has more than 4,000 nuns and runs more than 700 branches around the world. (dpa)