GUIYANG - The deaths of four children from one family in one of China's poorest regions have once again shed light on the plight of the vast number of children without parental care in the world's second largest economy.

Four young siblings were hospitalized after taking pesticides in Cizhu village, Bijie city in southwestern province of Guizhou on Tuesday, a police investigation confirmed.

Aged between 5 and 13, they died in the hospital after emergency treatment failed. It remains unclear whether they intended to kill themselves.

Local authorities were unable to get in touch with the children's parents.

Their mother, Ren Xifen, left home in March 2014 after a long and bitter feud with her husband, while the man, Zhang Fangqi, left the village for work in March this year, according to Gao Huacheng, the village's Party chief.

Caring for themselves, the siblings were living among 500 kg of stored corn and 25 kg of preserved meat in a three-story home.

Zhang sent money to a bank card he gave to his eldest son, police found. The local government has provided the family with minimum living allowance since 2012, with more than 3,500 yuan (about 560 US dollars) left on the bank card.

Pan Ling, a remote relative of the children, said they were socially withdrawn and often skipped class. The siblings' grandparents, normally charged with taking care of children whose parents have left the village for work, all passed away.

The government of Qixingguan District, which administers the village, has started a survey on "left-behind" children and asked education officials, school principals and village heads to keep a close eye on the children to prevent similar tragedies.

China has more than 60 million children in rural areas who are left to relatives, usually grandparents, by their parents away from home for better-paid jobs. According to a 2013 report released by the All-China Women's Federation, nearly 3.4 percent of the children live alone.