Which websites has China blocked?

It now appears that thousands of journalists arriving in Beijing to cover the Olympics will face a similar situation.

At the Olympic Main Press Centre, situated next to the main sporting venues, websites that are off limits include news sites.

The BBC's English-language website is available, but not the Chinese-language version, apparently "Internet Explorer cannot display the webpage".

Other Chinese-language news websites that have been blocked include radio station Voice of America and Hong Kong newspaper Apple Daily.

Also off limits is the website of Liberty Times, a Chinese-language newspaper published in Taiwan, a self-governing island that China considers its own.

Human rights organisations, too, appear to have fallen foul of the Chinese censors at the Olympic press centre.

Amnesty International, which this week published a report critical of China's human rights record, is not accessible.

Neither is the website for New York-based rights group Human Rights Watch.

Thorny issues

Also on the blacklist are some sites related to historical incidents that are deemed sensitive in China - such as the Tiananmen Square killings in 1989.

Hundreds, if not thousands, are thought to have died when Chinese soldiers opened fire on students and other protesters.

A Google search for "Tiananmen massacre" throws up a lot of results.

Some of them, such as a link to a BBC story on the incident, are accessible. Other websites, such as reference on Wikipedia, are not.

There are also restrictions on websites dealing with Tibet, which saw anti-government protests and riots earlier this year.

Websites advocating an end to Chinese rule in the Himalayan region have been blocked.

The Chinese government heavily censors information about Tibet to its own people - and Olympic journalists will also face these restrictions.

China has expressed pride in its facilities for journalists.

The Main Press Centre - which is for print journalists and photographers - is the biggest in Olympic history, serving 144 media organisations, China says.

But many journalists are already expressing anger at not being allowed unfettered access to the internet while covering the Olympics.

"This is not what we expected," said one furious German reporter.