China has become gripped by an internet campaign to trace children abducted and forced to become beggars, and reunite them back with their families – a movement that seems to have received a rare stamp of approval from the government.

Two weeks ago, Yu Jianrong, a prominent government critic, began a micro-blog to help rescue such children by urging people to post photographs of young beggars. The blog has since gathered 1,000 pictures, 100,000 followers and made several families happy.

On Tuesday, Peng Gaofeng, a migrant worker in Shenzhen, was reunited with his son who was kidnapped three years ago. Five other children whose pictures were posted on the blog were also identified by their parents, Chinese state media said on Wednesday.

Hosted by popular social networking site Sina Microblog, Mr Yu’s blog has led to other similar ones appearing on the Chinese internet.

Many initiatives that spread through microblogs in China quickly turn into confrontations with the government, as they tend to centre on abuses by local officials. Beijing often then orders the hosting site to block further comment.

However, in this case, the Chinese authorities appear to have jumped on the bandwagon, with state media reporting Mr Peng’s reunion with his son. Police in some cities have also joined the online campaign.

“Please take pictures of begging or stray children you encounter to provide leads for families,” said one official police microblog in Changzhou, in the eastern province of Jiangsu.

China estimates 20,000 children are abducted every year. Some are forced to beg by crime syndicates, while others are sold to couples who cannot have children, or are made to work in factories.

In India, child beggars and labour are still common, though many are thought to be put in work by their own impoverished parents. However, thousands of Indian children are also reported missing every year and newspapers often publish police reports of children who have disappeared. India’s National Centre for Missing Children, a non-profit group established in 2000, has 320,000 subscribers to its regular “kids missing alerts” which disseminate photos and data of missing children.

Mr Yu, who is also a researcher at the respected Chinese Academy of Social Sciences, has tapped into an existing online push by parents of abducted children in China. Organisations such as “Baby Come Home” or “The Ark” run websites with information on missing children.

However, his campaign, which marks the first time microblogs have joined the cause, has taken the movement to a new level. The social networking tool has spread rapidly in China during the past two years, cranking up the speed at which information travels and helping support the country’s fledgling civil society. “Everyone has a microphone,” Mr Yu told local media in December.

David Bandurski, a Chinese media expert at the University of Hong Kong, said the movement demonstrated both the power of social media in addressing social issues and how such tools challenged controls on public opinion.

The initiative has already generated criticism of the government. Wu Di, a blogger, asked where the government and police had been, in addressing the problem of abducted children: “Are the things the people can see invisible to our leaders?”