Local police are investigating a former construction official and his two sons in Harbin, Northeast China's Heilongjiang province, who set themselves ablaze on Monday to protest the demolition of their property.

Huang Dequan, former Party chief of Acheng district's urban construction bureau, and his two sons lit their petrol-doused bodies when confronting the demolition squad on Monday.

A spokesman for the district's public security bureau said on Tuesday that police are investigating the case, as the three men are suspected of threatening public security by dangerous means and violently resisting normal law enforcement.

All the 123 households, except the Huangs, in the district's outlying community, which is being demolished to make way for a steel company, have moved out, according to the local government.

Deputy Party chief of the district, Zhang Limin, said that, based on an assessment by a third party, the property of the Huang family is worth 1.05 million yuan ($157,658), but Huang asked for 10 million yuan in compensation.

Zhang said by Nov 24, local authorities had handed demolition notices three times to the Huang family, but Huang refused any mediation from local public security and land and resources authorities.

The leader of the demolition squad Xu Chaoyang said, when the demolition started, Huang's sons dashed out of the house to throw petrol-filled bottles toward them and attacked them with axes and sickles. Then the trio set themselves on fire and rushed toward the crew.

The fire was extinguished immediately by firefighters, who later sent the three men to hospital. Acheng People's Hospital said the father and one son had suffered second-degree burns, while the other son was slightly burnt.

Qu Xuewu, professor at the Chinese Academy of Social Sciences, said the police accusation is "far-fetched", as only when the demolition is legitimate, can the act be alleged as violently resisting law enforcement.