BEIJING — China has announced that individuals and groups are banned from privately adopting abandoned infants, in a country where tens of thousands are abandoned each year and where baby trafficking has been a perennial problem.

The Ministry of Civil Affairs announced Tuesday that people who find an abandoned child must immediately tell local residential committees and the police and not adopt the child at will.

The abandonment of children is a big problem in China. Its strict one-child policy — which limits most urban couples to one child and rural couples to two if their first-born is a girl — and a traditional preference for male heirs result in the abandonment of girls and disabled children. Poverty and the social stigma for unwed mothers are also factors.

China's adoption law forbids baby trafficking and trafficking abandoned babies in the name of adoption, but doesn't mention whether individuals are allowed to keep abandoned babies. The new rules that forbid keeping such babies are outlined in a document from several government departments that was posted on the Ministry of Civil Affairs's website.

The new rules say people wanting to adopt must go through official channels and meet requirements, which under Chinese law include being healthy, over 30 and childless.

People who use abandoned children for illegal and profitable ends will be severely punished, the rules say, without specifying.

The document also sets out measures that should be taken when an abandoned baby is found, requiring that police try to track down the parents or guardians, and transfer children to a government-sanctioned nursing home for temporary care if they fail. These homes should only take the children under official care if no guardian is found within a certain period.

China's chronically underfunded state orphanage system has been unable to adequately provide shelter for many of the children who have been abandoned, and such services have often been left to private citizens with few resources and no legal authority. In January, the issue was highlighted when a fire at an illegally run orphanage killed six children and one young adult.

Zhou Xiaozheng of Renmin University's School of Society and Population Studies said nearly 200,000 babies were estimated to be abandoned in China each year, mostly girls whose parents wanted to try again for a boy.

"It's good for the government to strengthen its management of abandoned children, but it will also bring revenue to the government because any potential adopters must pay a handsome adoption fee," Zhou said.