Two Chinese government officials tasked to enforce the country's one-child policy had been stabbed to death by a disgusted father after he was told he can no longer register his fourth and youngest child until he pays the fines for breaking the law.

Using a machete to kill the two officials, the father of four from China's southern Guangxi region likewise injured four others. The hand of one of the four had been severed.

Identified only as surnamed He, the father tried to apply for a hukou for his child. A hukou is a resident's certificate essential to obtain education, healthcare and government benefits.

The father's casualties included the Family Planning Bureau's director and deputy director. Among those injured was the deputy secretary.

China's 30-year-old one-child policy imposes family planning rules on its nationals. To enjoy education, health care and government benefits, urban couples may only have one child, while rural families may have two, but only if the eldest happened to be a girl.

For children born beyond those allowed limitations, the parents are required to pay a heavy fee or fine for the hukou, which sometimes goes 10 times more their annual income and depending on the province.

The official from the Family Planning Commission of Fangchenggang city said the suspect, a villager with one son and three daughters, was certified mentally disabled. Police authorities said the suspect had been detained.

It wasn't stated if he had previously paid a social compensation fee.

Footage broadcast provided by Guangxi TV showed the father being subdued by helmet-wearing police armed with long metals.