An online campaign to help people who have lost their only child has prompted China's netizens to help the country's elderly.

A large number of older people in China are left in financial and social limbo after their only child dies, Deng Fei, a journalist from the magazine Phoenix Weekly, said in his micro blog on Sina Weibo, a popular micro-blogging platform, on July 30.

Deng, who has 2.26 million fans on Sina Weibo, urged netizens to contribute ideas to help people who have lost their only child and struggle with problems related to aging.

Deng's message was forwarded about 3,000 times and commented on more than 1,000 times as of Monday afternoon.

Lu Jiehua, a social-demographics professor at Peking University and a member of the National Population and Family Planning Commission's expert team, told China Daily that an estimated 1 million households have lost their only child.

The online campaign is named Yinuanbingxin, which means "using the power of philanthropy to warm broken hearts".

Yu Wenyan, who is in charge of an online discussion group for volunteers in the campaign, said: "We have more than 400 volunteers in three QQ groups," referring to the instant-messaging service.

"One group is for people who can lend a hand to people who lost a child in their cities, one group is for people who want to share ideas for an old-age support system, and one is for volunteers who are legal experts or journalists."

Yu said two volunteers in Wuhan, Hubei province, visited Wang Baoxia, a 53-year-old mother in the city's No 5 Hospital. Wang needed surgery on her right leg. She had been disabled as a result of her deformed spine and a depressed sciatic nerve.

Wang lost her son in 2004 and divorced her husband two years ago.

The hospital initially refused to operate on Wang because she had no relative to sign the surgery agreement and the retired woman was unable to afford the surgery, Yu said.