Congress president Sonia Gandhi unfurled the national tricolour at the party headquarters here on the 73rd Independence Day on Thursday.
The flag hoisting ceremony was attended by many senior leaders, including former Prime Minister Manmohan Singh, former party president Rahul Gandhi, Salman Khurshid, Ahmed Patel, Bhupinder Singh Hooda, Kapil Sibal, Motilal Vora and Ghulam Nabi Azad.
The ceremony ended with the recital of the national anthem.
Congress Sewa Dal volunteers saluted to the national flag.
A group of children present on the occasion greeted Sonia Gandhi and Manmohan Singh who presented them sweets.