Doctors prepare to operate on 10-month-old conjoined twin girls at Fudan University's Children's Hospital in Shanghai, Thursday July 6, 2006. They shared a liver, spleen, gall bladder and digestive tract. Hospital officials say the separation surgery may take up to 24 hours.[newsphoto]

Doctors were racing to save the lives of 10-month-old conjoined twin girls on Thursday in a complex separation surgery expected to take up to 24 hours, hospital officials said.

The girls, Hu Jingxuan and Hu Jingni, were born last August joined at the abdomen. They share a liver, spleen, gall bladder and digestive tract.

Hospital officials confirmed reports that the surgery was under way but would not provide any details. The officials would not give their names.

The twins were suffering from heart and liver problems, forcing the doctors to operate in hopes of saving at least one if not both of the girls.

"They are joined in a very complicated way," Wang Yi, vice president of Fudan University's Children's Hospital, told the state-run newspaper Shanghai Daily. "The operation may be a big risk but we can't wait any longer because the twins' condition is getting worse."

The hospital, which has conducted many such operations, began planning the girls' separation surgery right after their birth. A business group in Taizhou, the twins' hometown, raised US$25,000 to help pay for their treatment, the newspaper said.

In recent weeks the babies, who were born weighing a total of 10 pounds, had stopped gaining weight, the report said. Before surgery, they weighed 16 pounds, it said.

State-run television said the medical team working on the girls managed to separate their livers after two hours of surgery.