Du Bin for The New York Times Ji Ke Ri Sha, 15, with his mother in Liangshan, China. He says he has spent more than a year working in factories in several provinces, including Shandong and Shanxi.

LIANGSHAN, China — The mud and brick schoolhouses in the lush mountain villages of this remote part of southwestern China are dark and barebones in the best of times. These days, they also lack students.

Residents say children as young as 12 have been recruited by child labor rings, equipped with fake identification cards, and transported hundreds of miles across the country to booming coastal cities, where they work 12-hour shifts to produce much of the world’s toys, clothes and electronics.

“Last year I had 30 students. This year there are only 14. All the others went outside to find work,” said Ji Ke Xiaoming, 35, a primary school teacher whose students in Erwu Village are mostly ages 12 to 14. “You know, we are very poor. Some families can’t even afford a bag of salt.”

China is now investigating whether hundreds, perhaps thousands, of poor children of the Yi ethnic minority group in Liangshan were lured or even kidnapped to work in factories that are increasingly desperate for the kind of cheap labor that powered China to prosperity over the past two decades.

Labor recruiters — government investigators and some local residents portray them as con men — have connected two radically different parts of China’s turbulent society. They have brought together ethnic minorities untouched by economic development in their mountainous isolation, and factory owners in the prime export manufacturing zones of southern Guangdong Province, near Hong Kong.

Exporters have struggled to adjust to soaring inflation, a fast-rising currency and, with some irony, stricter enforcement of labor laws that make it harder to hire regular workers on a seasonal basis. Using child workers from a remote region, many of whom cannot even speak Mandarin, the country’s main national dialect, have provided a temporary, albeit illegal, solution.

A scandal involving Liangshan’s children first came to light late last month, when Southern Metropolis, a state-run newspaper, reported that as many as 1,000 school-age workers from the area were employed in manufacturing zones near Hong Kong.

The report was deeply embarrassing for Beijing, which is preparing to host the Olympics and coping with international criticism of its handling of riots in Tibet. Last week, the authorities in Liangshan said they had detained several people for recruiting children and illegally ferrying them off to factories.

And officials in Dongguan, one of the manufacturing zones where the children worked, said that they had “rescued” more than 160 young people from factories. The legal minimum working age in China is 16.

Now, officials have begun to play down the scandal, saying there is little evidence of widespread violations of child labor laws. A two-day government sweep involving more than 3,000 factories around Dongguan, which was conducted after the initial raids, turned up only 6 to 10 children, officials said.

The New York Times Some Lianghsan children take work in Shandong Province.

But residents of Liangshan say abject poverty, drug abuse and a lack of jobs have forced many children to head for factories. Sometimes it is with their parents’ permission. Other times, children disappear, on their own or with job recruiters, and then call home from a factory dormitory, hundreds of miles away.

“When our daughter left, we were quite worried,” said 42-year-old Qi Ji Gu Xi, whose 14-year-old daughter left last February. “We didn’t know where to find her. Then she called us and told us she’s a migrant worker in Guangdong.”

Such stories are not unusual. In more than two dozen interviews this week, children who had returned home from factories told of hardship and abuse. Parents living in squalor acknowledged that their children had been lured into traveling to factories. And other residents said conditions in these mountain villages were so appallingly poor that young people felt they had no choice but to leave home.

On Wednesday, more than 10 families interviewed in the span of five hours in Zhaojue County, part of Liangshan, said they had children working in factories, often earning less than $90 a month for 12-hour days, seven days a week. Even if the children were of working age, the pay, equivalent to about 25 cents an hour, and the working conditions would violate China’s labor laws. In the prime manufacturing zones, the official minimum wage is at least 65 cents an hour, and employers are required to pay significantly more for overtime.

Ji Ke Ri Sha said he had spent more than a year working in factories in several provinces, including Shandong and Shanxi. His family could not survive on farming alone, he said, and so he took a chance on the world outside. He hopped from factory to factory, holding four jobs before his 15th birthday.

“My father worried about me going away, but we had no money,” he said quietly, squatting on the mud floor of a farmhouse. “I had to go outside, but the work turned out to be too difficult.” An employment agent persuaded his parents that he could find their son a factory job. But the boy says the agent ended up making a secret deal with a factory, and pocketing half the boy’s pay as a finder’s fee.

Liangshan, formally known as the Liangshan Yi Autonomous Prefecture, may have become a target of child labor rings precisely because it is a place of desperation. The villages, populated almost exclusively by Yi, are reached by traveling for hours along winding roads through the thickly forested part of Sichuan Province. Most people survive on subsistence rice farming. Others fall prey to the drug trade. One of the main heroin trafficking routes passes through these parts on the way from northern Myanmar to Chengdu, the largest city in the region.

The area is plagued by drug abuse and AIDS. Many people have no formal education and cannot converse in Mandarin, making it difficult to seek employment in cities on their own.

Luo Gu A He, 69, said his 14-year-old granddaughter left Keqie Village for Beijing in March, after the death of her father, who had been addicted to drugs. She now earns about $4 a day working seven days a week at a construction site, he said.

“She is too young,” the grandfather said. “I worry about her being alone in Beijing. But if she stays with me she couldn’t live either; she’d starve to death.”

A woman spoke of a daughter who left home at 15 to work in a brick factory in Shandong Province but returned recently. “My daughter was taken by a foreman,” said the woman, Pa Cha Ri Gu, 62. “I was concerned, but we are poor. You see the small house we live in.”

Residents say they have heard of children being kidnapped and forced to work in factories. Other villagers say that desperate parents, some addicted to drugs, resort to selling their children to child traffickers.

As the supply has grown, so has the demand. Over the past few years, coastal factories have complained of labor shortages and said many migrant workers were reluctant to work for low pay on factory campuses in the country’s coastal provinces.

Factories find themselves caught in a squeeze between foreign buyers, who are addicted to lower prices for manufactured goods from China, and surging food and energy costs. Profit margins, never very fat, have shrunk, and Beijing has passed new labor laws that restrict the use of temporary workers.

Employment agents have come to the rescue, providing the factories with pliable children who carry falsified documents attesting that they have reached the legal working age, state news media and local parents said. They take half the child’s wages, but people in Liangshan are hungry for any cash income.

During an interview with a group of residents in Keqie Village, a man in a leather jacket initially spoke up and identified himself as an employment agent, but then declined to give many details, saying only, “I help them find a way out.”

Chen Yang contributed research.