Officials in Changshu, Jiangsu province, found eight child laborers on Tuesday after an online video exposed the illegal use of underage workers in garment factories.
The local government found the child workers after searching nearly 2,000 workshops and companies.
The children will be accommodated in a school and sent home after the government helps them to get their salaries, China News Service reported.
The government took action after a video uploaded to pearvideo.com, a video website, went viral online. It featured several unnamed sources, their faces obscured, who said agents had cheated people, including children under 16 years old, from Yunnan province by promising them high wages.
According to Chinese law, companies cannot employ people younger than 16.
One source said that although the agents promise a monthly wage of 3,000 yuan (5), the child laborers sometimes make less than half of that.
He also said they asked the workers to hand in their identity cards and bank cards in case they tried to run away. Workers cannot get paid if they quit before they worked for a whole year, and even have to pay for traveling and living expenses if they quit after one or two months, the source said.
He also said the agents resort to violence if they failed to keep the workers in their jobs. If the children "don't obey", he said, they "will be beaten".
"After they are beaten, they work fast," he said.
A 15-year-old from Yunnan's Wenshan Zhuang and Miao autonomous prefecture, who was identified only as Xiaoxiong, said the boss kept his ID card and took away his computer.
"I was asked to pay 3,700 yuan after I went to work for another factory and was found by my former boss," he said.
Xiaoxiong said he could work on 350 pieces of clothing in one shift. But the boss asked him to increase that to 500. "I thought it wouldn't be tiring to work on clothes, as you aren't exposed to the sun. I never expected it to be so tiring," he said.
On Monday, police detained the manager of an illegal clothing workshop that hired child labor. The workshop doesn't have a license, the government said.
An official told China Youth Daily that there are about 4,000 clothing factories in Changshu, but such cases usually happen in illegal workshops without licenses that change their locations frequently.
The Changshu government has found 211 child laborers in 107 cases since 2012, China News Service reported.