Chinese doctors separated a set of twin girls who shared parts of their hearts, livers and intestines, but one of the newborns died less than two days after the operation, state media reported Thursday.

The girls were six days old when a team of four doctors carried out the six-hour surgery to separate the twin's livers, reposition their hearts and divide a shared intestine, the official Xinhua News Agency said.

One of the girls died Thursday, less than 48 hours after the surgery, from heart and lung failure, the agency said, citing lead surgeon Dr. Shi Dekun at the People's Liberation Army Hospital No. 303 in Nanning, the capital of south China's Guangxi region.

The other baby was in relatively stable condition, Shi said.

It is rare to perform separation surgery on newborn conjoined twins but doctors felt they had no choice because the girls were suffering from pneumonia, Shi said.