Updated

India's ruling Congress Party says its leader Sonia Gandhi has undergone surgery abroad for an undisclosed ailment.

A party statement Friday said that Gandhi had the surgery Thursday and "the surgeon indicated that the operation was successful."

The statement said that Gandhi was recovering in an intensive care unit.

It gave no details of her illness or the location of the hospital. News reports have said the operation took place in the U.S.

Italian-born Gandhi, 64, is the widow of assassinated Prime Minister Rajiv Gandhi. She declined the premiership despite leading the party to win 2004 elections.

In her absence the party is being run by a four-member committee including her son, Rahul, who is seen as a prime minister-in-waiting.