China has the world's biggest online population: more than 380m users

China has tightened controls on internet use, requiring anyone who wants to set up a website to meet regulators and produce ID documents.

The technology ministry said the measures were designed to tackle online pornography, but internet activists see it as increased government censorship.

A number of websites are now being registered overseas in an attempt to avoid controls.

China has the world's biggest online population: more than 380m users.

The Ministry of Industry and Information Technology on Tuesday lifted a freeze introduced in December on registration for new individual websites.

Extensive censorship

But the technology ministry said would-be website operators would now have to submit identity cards and photos of themselves, as well as meeting regulators before their sites could be registered.

The freeze had been imposed by the state-sanctioned group which registers domain names, after complaints by state media that not enough was being done to screen websites for pornography.

The BBC's Quentin Sommerville in Beijing says that despite extensive censorship, the internet remains a surprisingly vibrant and critical environment in China.

Internet users have used it to highlight cases of injustice or to embarrass corrupt officials.

China's web users often manage to stay one step ahead of government controls, says our correspondent.

The Chinese authorities have launched a number of campaigns against online pornography, with the government saying thousands of people were detained last year alone.