Rural Chinese children increasingly risk being sold orforced to become beggars, petty thieves or sex workers as their farmer parentsflock to cities looking for work, an international rights group said.

Chinahas a thriving black market in girls and women who are sold as brides, as wellas babies who are abducted or bought from poor families for sale to childlesscouples or those who have one child and want more.

The government says that it has cracked down harshly on such cases, and thatthe trend is decreasing.

But Kate Wedgwood, Save the Children's country director for China and NorthKorea,said there are no reliable figures for the number of children being traffickedand the continued mass migration from farms to cities is sure to make theproblem worse.

"We already know the risks (of child trafficking) are exacerbated bymigration, so I think the likelihood is that it will increase," she said.

In recent years, an estimated 150 million to 200 million people have movedfrom the countryside to urban areas where their labor in factories and onconstruction sites has fueled China'sbreakneck economic growth.

Several hundred million more are expected to leave China's vastrural hinterland over the next 15 to 20 years.

Poor rural children from ethnic communities are the most atrisk because they have limited command of Mandarin Chinese and often don't knowtheir rights, Wedgwood said. Disabled kids and children of parents with HIV/AIDSalso face increased risk of being trafficked and are sometimes forced intopanhandling.

She estimated that there are tens of thousands of boys from far western China's Xinjiang region who have been bought orkidnapped by gangs who force them into pickpocketing and other nonviolent crimein China'seastern cities.

Ethnic minority girls from Yunnan provinceand the Guangxi region in the south are at risk of being forced into the sextrade within China and alsoin Southeast Asian countries such as Thailandand Malaysia,she said.

Children left behind in villages are vulnerable because they are oftenlooked after by grandparents — who often need care themselves — or byinstitutions that lose track of the children.

However, those who migrate with their parents are also in danger becausethey are thrust into unfamiliar surroundings with limited social services, andtheir parents are often busy working.

Wedgwood wants Chinato redefine child trafficking to include victims up to 18 years of age andchildren who are forced into work to pay off family debts. China currentlydefines victims of child trafficking as kids up to 14 years old who are sold orkidnapped.