Congress party leader Sonia Gandhi has made her first public speech in India since undergoing surgery in August in the United States.
She spoke at a Congress youth rally in Delhi that was organised by her son Rahul and attended by Prime Minister Manmohan Singh.
The BBC reports Mrs Gandhi, 64, was greeted by cheers from thousands who attended the rally on Tuesday.
The party has repeatedly refused to comment on her illness, but reports suggest she was treated for cancer.
Mrs Gandhi reportedly looked tired but spoke for more than 10 minutes.
''You have the power to beat back the forces of oppression and injustice and to make a beautiful life for yourself and for others,'' AFP news agency quoted her as saying.
Mrs Gandhi is the widow of former Prime Minister Rajiv Gandhi. She heads the Nehru-Gandhi dynasty, which has ruled India for most of the time since independence in 1947.