Congress president Sonia Gandhi returned home yesterday after undergoing surgery for an undisclosed ailment in the US but it wasn't clear when she will resume her public life.

The 64-year-old flew into the capital at 3 am, said party general secretary Janardan Dwivedi. "Her health condition is fine," Dwivedi said.

Gandhi went to the US in early August. The nature of her ailment was never disclosed.

Congress leaders said they were not sure when she will return to active politics. "She will take the advice of doctors," one of them said.

Congress sources feel she would be forced to rest at least for a while. The Congress did not hold its customary media briefing yesterday.

Although Gandhi had named a four-member panel including her son and general secretary Rahul Gandhi to oversee the country's oldest party when she was away, the Congress felt her absence during the Anna Hazare fast.

Besides Rahul Gandhi, she had named Dwivedi, Defence Minister AK Antony and her political aide Ahmed Patel to take charge of the Congress.

Barring Rahul Gandhi, who was in regular touch with her mother, the other three remained mostly low key when Hazare's campaign against corruption led to nationwide protests, forcing the government to bend.