The latest tragedy in a string of bloody cases of forced demolition in the country occurred on Tuesday in Shanghai, when a 49-year-old man died while trying to protect his house.

The victim, Zhou Daming, was "besieged" and "pushed" by a group of 20 men who came to notify him of the impending demolition of his house, located in downtown Shanghai's Huangpu district. When the men dispersed, Zhou was found lying unconscious, said witness Zhou Juhua, the victim's sister.

The man died half an hour later, despite emergency treatment by the nearby 120 medical emergency center, his sister said.

It was not clear whether the demolition squad beat the man, as he had no obvious injuries, she said.

The possibility that the man, who suffered from high blood pressure, might have died from a sudden rise in blood pressure due to stress or anger could not be ruled out, she said.

Zhou Juhua said that in that case the men in the demolition squad should still be held responsible.

Shanghai municipal government did not comment on the incident on Wednesday, and reporters were barred from entering the demolition area.

By press time, Zhou's body was still lying at a temporary mourning hall set up by his relatives at the demolition squad's office. The family members were insisting that the authorities should give them a fair and convincing explanation about how Zhou died before they allowed the body's removal.

According to information on the local government's website, the demolition project is making way for a low-rent and affordable housing project.

The project, started in late 2008, was stalled during the World Expo and resumed recently. So far, more than 75 percent of the houses in the designated area have been demolished.

The victim's family had not yet reached an agreement with the property developers over compensation. The family of one sister and two brothers, who live in a cramped 46.2-square-meter house with their children, insisted they should be compensated as three households instead of one.

The incident came only one day after a former construction official in Northeast China's Heilongjiang province and his two sons set themselves on fire to protest against the demolition of their property. Local police said the three may face charges of threatening public security by dangerous means and violently resisting normal law enforcement.

China has witnessed a long list of forced demolition cases, in which disgruntled property owners have resorted to extreme means to protest against the forced destruction of their houses.

China's current regulation on urban housing demolition allows governments to acquire people's houses for public projects. The government and real estate developers sometimes hire professional demolition companies to negotiate with people or even force them to move out.

In the face of rising public discontent, the Legislative Affairs Office of the State Council in January published a draft amendment to the existing regulation to seek public opinion, but no progress has been reported since then.

The draft amendment stipulated that houses could only be demolished to serve "the public interest". Residents must be paid full compensation before they move out. Relocations can take place if at least 90 percent of residents agree with the compensation proposal.

But Zhou Yuting, niece of victim Zhou, told China Daily that when she challenged the demolition squad with the draft amendment, they said that the amendment had not yet come into effect and that they had the right to forcibly demolish the house.

Controversies over the legitimacy of this project have been simmering for the past two years.

Residents living in the apartment building opposite the demolition project said the planned 35-storey building would block the sunshine and the view from their 30-storey building.

"We strongly insist that the government should revise the plan, because we paid a high price for our apartments and we don't want to live here without enough sunshine," said Xu Dasheng, a resident living on the 16th floor.