A heart-wrenching picture of a four-year-old from South Sudan begging for some water from Chinese peacekeepers has tugged the heartstrings of netizens.

The emaciated boy in rags, named Bol, was pictured gulping water from a watercart, and bursting into a broad smile after quenching his thirst.

Chinese squadron commander Yin Guoqiang said the boy followed their convoy, and threw himself to the pipe as soon as they arrived at the water distribution point. Yin helped Bol when he found the little thing was too weak to open the tap.