Sonia Gandhi recovering from surgery

Her party’s statement issued on 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. Janardhan Dwivedi said the "surgery is over [and] the surgeon had indicated that it was successful".

Gandhi was "likely to be away for two to three weeks", he said.

Gandhi, 64, is India's most powerful politician. She holds no official post but many consider her the de facto head of the government.

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.

Gandhi's absence from the parliament on Monday was remarked upon in the Indian media, but explained by a "viral infection" from which she was said to be suffering.