A Chinese law requiring family members to visit their elderly relatives went into effect Monday to howls of online ridicule, as the country's huge population ages rapidly.

The regulation "forces" children to visit their parents, the state-run Global Times newspaper said, with concerns growing over increasing numbers of "empty nest" homes.

China's rapid development has challenged its traditional extended family unit, and reports of elderly people being neglected or mistreated by their children have shocked the country.

Last year a farmer in the eastern province of Jiangsu faced a barrage of online criticism after domestic media revealed he had kept his 100-year-old mother in a pig sty.

More than 14 percent of China's population, or 194 million people, are aged over 60, according to the most recent figures from the National Bureau of Statistics.

The growing proportion of the elderly is the result of China's controversial one-child policy, which was launched in the late 1970s to control population growth.

Many aged live alone in "empty nest" homes, as a result of their children finding work in other areas of China.

But while Internet users generally express concern for elderly people -- who are highly respected in the close-knit Chinese family unit -- many took to China's Twitter-like microblogs to criticise the new measures.

"A country actually legislates respecting its parents?" said one of the eight million people to comment on the story on Sina Weibo.

"This is simply an insult to the nation."

Another poster said: "The government uses legislation to protect the elderly, but in reality it is just to put all the blame on to their children.

"The government should have thought of how they would address this problem when it brought in the one-child policy."

The state-run Shanghai Daily said the new law gives parents the power to apply for mediation or bring a case to court, but experts are unclear about how the measures will be enforced, or how often visits are required.

"More quantitative standards and measures need to be added," Xia Xueluan, a professor with Peking University's Institute of Sociology and Anthropology, told the Global Times.

"The current revision looks more like a reminder for young people to refocus on the traditional values of filial piety rather than a compulsory law," he said.