During several hours of confrontation, the village Communist Party headquarters was ransacked, and at least two victims were reported beaten to death. Dozens were injured.
Tension between migrant workers and locals runs high in most of China's economically advanced cities and coastal provinces. Poor farmers who flood in from inland say they are treated with contempt by locals, though they do most of the hard labour and dirty jobs that no one else wants. The locals blame the migrants for soaring crime and overburdened local services.
Shenzhen, bordering Hong Kong, has one of the world's fastest growing economies. Its Special Economic Zone was China's first experiment with capitalism 15 years ago. Many factories depend on cheap migrant labour to churn out billions of pounds' worth of goods for export.
According to Hong Kong newspapers, two of which published photographs of a dead migrant worker on a hospital bed, the clash took place in Longtian village, in the north-east of Shenzhen, outside the special zone. The labourers, from Hunan and Hebei provinces, were working for a Chinese construction company building a motorway.
On Sunday morning, a villager on a motorbike disregarded barriers and rode down a section of newly-tarred road. The infuriated workers attacked the rider, who used his mobile telephone to call the police. Armed Public Security Bureau men and private village security guards arrived. A gun was held to the head of one of the workers by a policeman. The officer was attacked by labourers with shovels and metal bars, and a full-scale battle ensued.
The migrants called in support from a nearby construction site, and a reported 500-strong mob descended on the village and the party office. Riot police were called in and opened fire with automatic weapons. One migrant worker and one onlooker were shot dead. A village security guard and another migrant worker were beaten to death, and about 10 labourers were in critical condition. Dozens were arrested. Longtian was yesterday reported to be under tight security.
Such clashes are believed to be common in China, but usually go unreported. Details of this one filtered out because it happened close to Hong Kong.