Despite efforts to pull millions out of poverty in China over recent decades, the country still lacks modern child welfare systems seen in the West, Rutstein said.

"The concept of social workers, for instance, which is quite well known in Europe and North America, is very, very new in China. China's aware of this and there are many efforts in place right now to professionalize the whole system of social workers, to introduce alternatives to institutionalization, or just sending children to a state orphanage, which traditionally has been the main response to these kinds of situations," he said.

An opinion piece published Wednesday in China Daily asked whether authorities were too quick to lay the blame on local officials and suggested that major changes were needed to reduce the number of "left behind children."

"This tragedy is a wake-up call that something needs to be done to improve the working and living conditions of migrant workers, so they can settle in the cities where they work and enjoy the same rights as their urban counterparts. This would enable them to have their children live with them," it said.

The plight of the dead children in Guizhou has been compared on social media to the tale of the Little Match Girl, a Hans Christian Anderson story of a girl ignored by the rich who froze to death after trying to warm herself with a lit match.

On Wednesday, messages of condolences for the five boys were still being posted on Weibo.

"Hope they won't feel cold anymore in heaven," @Qingyu_aneya said.

@KongXia added: "Rest in peace, don't reincarnate in China..."

Referring to Beijing's decision to turn on the city's heating system two weeks early this year due to colder temperatures, one of China's most popular fairy tale writers, Zheng Yuanjie, posted: "Beijing spent 800 million [yuan] to start the heating system 15 days ahead of time, but you're out of the reach. Hope the 'The Little Match Boys' can forgive us in heaven."

The boys were Tao Zhongjing, 12; Tao Zhonghong, 11; Tao Zhonglin, 13; Tao Chong, 12; and Tao Bo, 9.