Modi said in a tweet: "Tributes to our former PM lndira Gandhi on her birth anniversary."

Also in a tweet in Hindi, Rahul Gandhi said that his "beloved grandmother" was blessed with a strong, capable leadership and amazing management ability.

He said she was an "iron woman who played a key role in establishing India as a strong country".

The Congress party also paid tributes to its late leader

"On her birth anniversary we pay homage to India's first female Prime Minister, the Late Indira Gandhi. Her will and determination led our country to great heights. Her contributions to India's national security, economy and foreign policy will always be cherished," the party tweeted.

She was born on this day in 1917 to Jawaharlal Nehru, the first Prime Minister of India, and his wife Kamala Nehru, a freedom fighter.

Indira Gandhi served as Prime Minister from January 1966 to March 1977 and again from January 1980 until her assassination in October 1984.