Updated

An official says India's opposition Congress party leader Sonia Gandhi has been hospitalized for treatment of lower respiratory tract infection.

Ajay Maken, the party spokesman, says Gandhi was admitted to New Delhi's Ganga Ram Hospital on Thursday, according to the Press Trust of India news agency.

Janardhan Dwivedy, a party leader, confirmed that Sonia Gandhi was unwell.

Gandhi is the Italian-born widow of slain former Prime Minister Rajiv Gandhi. After his death, she entered politics reluctantly but has led the Congress party to successive election triumphs in 2004 and 2009.

The Congress party has long kept a careful veil over Gandhi's personal life despite her immense influence. She flew to the United States for a surgery in 2011, with some Indian news outlets saying she had been treated for cancer. But the party never gave more than cursory information about her illness, calling it a personal matter.