The weaker of 10-month-old conjoined twin girls who were separated in an unusually complex surgery last week died Monday, the Shanghai hospital treating the babies said.

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 at the Fudan University Children's Hospital had branded last Thursday's separation surgery a "miracle" but had cautioned that the girls, who also suffered from congenital heart disease and other problems, were still in precarious condition.

Hu Jingxuan's condition deteriorated over the weekend and she died Monday afternoon, said an official in the hospital's administration office. The official, like many Chinese, refused to give her name because she was not officially authorized to speak to media.

Chen Jingni, the stronger of the twins, was in stable condition, the official Xinhua News Agency reported.

Doctors said they were forced to operate last week because the girls had stopped gaining weight and could both die if they were not separated.

The babies, who were born to a farm family, shared a liver, spleen, gall bladder and digestive tract before the 13-hour-long surgery.

The twins were born weighing a total of 4.4 kilograms (10 pounds). Before surgery, they weighed 7 kilograms (16 pounds), it said. They looked thin and frail in photos provided by the hospital.

The hospital, which has conducted numerous separation operations, began planning the girls' surgery right after their birth. A business group in Taizhou, the twins' hometown, raised more than 200,000 yuan (US$25,000;euro20,000) to help pay for their treatment, reports said.