The Chinese government is drafting tighter rules on adopting children to combat the country's widespread child trafficking problem.

The China Daily newspaper says only orphanages will be able to offer abandoned infants and children for adoption. Adults who adopt children without official registration will not be recognized as legal guardians. The new rules are to be introduced by the end of the year.

Scores of exploited children are bought or kidnapped by gangs who force them into nonviolent crimes such as pickpocketing. China Daily says a study by the country's Center for Children's Welfare and Adoption has found that other children are sold to childless couples to carry on the family line and guarantee the parents security in their old age.

Ji Gang, an official at the center, tells the newspaper that forcing adults to go through official channels will reduce the demand for abducted children.

On Monday, eight people were convicted of kidnapping or murdering children in five separate cases. In one case, three men who lured children in Xinjiang into their trafficking ring were convicted for beating a young boy into a coma, then throwing him into a river.