Indian doctors said on Thursday that they have successfully completed a second round of reconstructive surgery on the skull of a baby suffering from a rare disorder that caused her head to nearly double in size.

The four-hour-long surgery on the skull of one-year-old Roona Begum was carried out at a hospital near New Delhi where last month surgeons also drained fluid from the youngster's head in a life-saving operation.

"Today's surgery was the biggest one so far in terms of remodelling her head. I think it went pretty well," neurosurgeon Sandeep Vaishya said inside the operating theatre.