London, July 7 : The coastal city of Xiamen in China's southeastern Fujian province has announced a ban on anonymous online postings, after residents mounted a successful internet campaign against proposals for a huge chemicals factory.

Henceforth, Internet users will have to provide their real names, backed up by data from their identity cards, when posting messages on more than 100,000 websites registered in Xiamen.

Authorities decided to impose the ban after thousands of residents in the port city marched through the streets, used their mobile phones to send text reports, as well as photos and videos, to bloggers and websites in other cities, which posted live reports of the march.

The local government has since suspended the construction of the 700 million pound chemicals plant, pending an investigation into the potential environmental risk.

Tian Feng, vice-director of the Xiamen Bureau of Industry and Commerce, was quoted by The Times as saying that a new law, the Measures for Management and Disposition of Harmful and Unhealthy Information on the Internet, would be announced soon by the city government.

A government official said that the protest had shown the necessity to control content on the internet.

Internet censorship is common in China, where the Government employs an elaborate system of filters and tens of thousands of human monitors to survey the surfing habits of its 140 million internet users.

Dozens of outspoken journalists and internet commentators are serving lengthy prison terms after being jailed on charges such as subversion or leaking state secrets. Internet caf
és are required to inspect and register the identity cards of all users, but this is not widely enforced, particularly outside the larger cities.