SHANGHAI (Reuters) - Hundreds of people marched through China's financial hub of Shanghai on Saturday protesting a planned extension of the city's magnetic levitation train, or "maglev", worried it would emit radiation and sicken them.
Police initially detained dozens of people, bundling them into waiting cars, vans and buses, as protesters gathered in front of city hall shouting "We don't want the maglev" and carrying placards reading: "No to maglev -- bad for health".
"We are afraid how the radiation will affect us. Why does the government not listen to our concerns?" said a protester surnamed Guan, adding the extension would pass within 100 meters (328 ft) of her house.
As police cordoned off the city government in People's Square, once home to a race track in Shanghai's colonial heyday, demonstrators took off down the fashionable Nanjing Road shopping area.
The protest was the largest the cosmopolitan and wealthy city has seen since thousands took to the streets in sometimes violent anti-Japanese demonstrations in 2005.
"I'm marching against the proposed line as it's too close to town. It's going to be noisy and emit pollution," said another protester, who would only give his family name, Liu.
"If you have a house near the line, you will not be able to sell it for as much money," he added.
Some demonstrators handed out anti-Nazi resistance poems in German, while others sang the Chinese national anthem.
In a prepared statement, a spokesman for the Shanghai city government said authorities had "persuaded" the protesters to disperse because they were affecting public order.
He said the government was still in the process of showing to the public a proposal for the maglev project, which would help to improve the transport system of the city and the whole country.
"We hope city residents will go through legal channels to express their opinions rationally, and not use methods that affect public order," he added.
The protest gradually dispersed peacefully under a light drizzle in the early evening. The police kept their distance as people left.
The country is grappling with an acknowledged rise in unrest, driven by anger at illegal land grabs, corruption, environmental woes and a rising rich-poor gap, though large scale protests in big cities are rare.
"Yes, it's an illegal protest. But we've been pushed into a corner," said another protester.
EXTENSION PLAN "SAFE"
China has the only commercial maglev in operation in the world, developed and built by the government and a German consortium including industrial giant Siemens.
Launched in 2003, the maglev floats on a magnetic cushion over a distance of 30 kilometers (18.6 miles) between an outlying part of Shanghai's financial district in Pudong and the international airport.
The government wants to extend the train to downtown Shanghai, and then possibly to the nearby tourist city of Hangzhou.
An environmental assessment report released by the Shanghai Academy of Environmental Sciences this month, compiled for the government after complaints by city residents, declared the extension plan was safe.
The maglev line would not affect air and water quality, and noise pollution could be controlled, the official Xinhua news agency quoted the report as saying.
However, Xinhua also quoted the report as saying a greenbelt buffer zone around the track would only be 22.5 meters wide, though an original blueprint by the local government showed a buffer zone of 150 meters on either side, and German specifications required 300 meters on each side.
Authorities planned to limit the maximum speed along the Shanghai section of the route to 200 km per hour, about half of the maglev's speed on the existing section of track from the international airport, Xinhua said.