Riot police were called in to rescue the mayor when former military construction workers surrounded him while protesting their compensation in China's showcase business city of Shenzhen, news reports said Tuesday.
The protests by up to 5,000 former employees of the army's construction corps highlight festering resentment over losses of pay and benefits as government companies, often headed by corrupt managers, are converted into private enterprises.
Authorities tried to suppress news of the protests, and details were sketchy.
According to Hong Kong newspapers and Radio Free Asia the protests began last week in the southern city of Shenzhen, adjacent to Hong Kong, as workers took to the streets demanding more compensation from their companies.
The demonstrations ran through the weekend, with the workers surrounding a local police station to demand the release of two protesters detained by police, Hong Kong's Ming Pao newspaper said.
It said the workers had been paid only a few hundred euros in lieu of company shares they expected to receive following a government-ordered pay system restructuring.
Shenzhen Mayor Xu Zongheng met with the protesters Monday and promised a high-level investigation into their complaints, but the workers surrounded him and kept him from leaving until riot police were called in to rescue him, news reports said.
The army workers and engineers were sent to Shenzhen in the early 1980s to help turn the former swampy fishing village into a showcase city of broad boulevards, shiny office towers and massive factories.
The construction corps was later divided into state-owned enterprises that are gradually being converted into shareholding companies, with the city government retaining majority ownership, the AP reports.