Premier Li Keqiang has ordered the full implementation of the country's temporary relief system and stronger government oversight of "left-behind" children in the wake of a case in which four siblings committed suicide by drinking insecticide in Bijie, Guizhou province.

Li said central government departments should increase the supervision of work at local levels and enhance the implementation of the temporary relief system, according to a statement released on the central government's website on Friday.

The four siblings were left behind in their home alone after the father, Zhang Fangqi, left for Guangdong province in March to work. The mother, Ren Xifen, left the family in March last year after a fight with her husband that left her hospitalized.