A man in south China's Guangxi Zhuang Autonomous Region threw a two-year-old boy from a room on the sixth floor of a building during an argument with the kid's mother, killing the youngster, local police said on Saturday.

The boy died in hospital, according to police in Nanning, capital city of Guangxi.

Police said they received a call saying a child was falling from a building Friday afternoon.

Police later linked the incident to a man surnamed Lu, who confessed that he threw the child off the building because of a "romantic dispute" with the boy's mother.

The kid had no biological connection with the suspect, a policeman said.

Lu is in police detention.