Australian surgeons are still trying to separate the brains of conjoined twins Trishna and Krishna almost 24 hours into the operation.
Surgery to separate the twins, who are joined at the head, began about 8.30am on Monday.
A spokeswoman for the Royal Children's Hospital told AAP shortly after 7am on Tuesday surgeons were still in the process of separating the girls' brains.
After their brains are separated, the final piece of shared skull will be removed to allow plastic surgeons to reconstruct the girls' skulls using a combination of their own skin, bone grafts and artificial materials.
The hospital will update the media on the progress of the operation at 7.45am (Australian Time).
On Monday night the director of anaesthesia and pain management at the hospital, Dr Ian McKenzie, said the girls and the surgical team were doing well.
The groundbreaking bid to save the Bangladeshi orphans comes two years after they arrived in Australia through Moira Kelly's Children First Foundation.
The chances of the operation being a success have been put at just 25%.
