New Delhi, Nov 19 (ANI): Congress president Sonia Gandhi and party vice-president Rahul Gandhi on Wednesday offered floral tributes to former Prime Minister Indira Gandhi on her 97th birth anniversary. President Pranab Mukherjee, Vice President Hamid Ansari and former Prime Minister Dr Manmohan Singh also offered floral tributes to India's first woman Prime Minister at her memorial in Shakti Sthal.