Local authorities have detained nine people, including an obstetrician, on suspicion of baby trafficking at a hospital in northwestern China, according to state media.

Three government officials and three hospital managers at Fuping County Maternal and Child Health Care in Shaanxi province were also dismissed over the baby trafficking scandal, Xinhua News Agency reported.

The obstetrician has been named as Zhang Shuxia and it is alleged that she abducted newborns after sometimes falsely claiming healthy infants were born with congenital problems.

It is not clear whether the other eight held worked at the hospital.

Xinhua said police had received 55 reports of child abductions and that Zhang allegedly was involved in 26 of them. It said police had rescued twin baby girls and located a third child, all taken from the Fuping hospital.

Al Jazeera's Harry Fawcett, reporting from the village of Xue Chen in Shaanxi, said the case has gripped China with the country's media descending on the small hamlet to record the reunion of the twin girls and their parents.

He said that one of the twins had already been sold to another female doctor who says that she was told the girl was the unwanted child of a young student.

Despite severe punishments, including the death penalty, child trafficking is common in China. The trade is very profitable, and demand is strong, driven partly by the preference for male heirs and a strict one-child policy.

"A lot of adoptions go abroad, a lot of adoptions go to the United States. And, while a lot of that is understood to be well regulated, there is a network of child trafficking that's proved very difficult to get rid of," our correspondent said.

Given the number of cases Zhang is charged with, she could face the death penalty.