China blocked access to Twitter, Flickr and other websites Tuesday, two days ahead of the 20th anniversary of the Tiananmen Square crackdown, Reporters Without Borders (RSF) said, expressing "outrage" at the move.
"Reporters Without Borders is outraged by the blockage of a dozen websites such as Twitter, YouTube, Bing, Flickr, Opera, Live, Wordpress and Blogger in China," the media rights group said in a statement.
"The Chinese government stops at nothing to silence what happened 20 years ago in Tiananmen Square," it said.
"By blocking access to a dozen websites used daily by millions of Chinese citizens, the authorities have opted for censorship at any price rather than accept a debate about this event."
RSF said it had been notified by Chinese Internet users that access to the websites began being blocked inside China on Tuesday.
A spokesman with the US State Department said there would be a more expansive US response on Wednesday, but underscored that US policy "supports freedom of expression."
"With regard to any activities that the Chinese government is undertaking in connection with the anniversary ... we will have more to say tomorrow through a statement on the anniversary," State Department spokesman Robert Wood told reporters.
The spokesman added that "the issue of human rights is a very important element of our relationship with China."
There was no immediate comment from Microsoft, which recently launched its new search engine Bing; Yahoo!, which owns photo-sharing site Flickr; or Twitter to emails from AFP asking about the reported move by China.
Google-owned YouTube has been blocked inside China since March.
China's foreign correspondents' association on Tuesday condemned moves by authorities in Beijing to block reporting in the run-up to the anniversary of the Tiananmen Square crackdown.
The Foreign Correspondents' Club of China (FCCC) said it had received at least three reports of authorities blocking reporting at Tiananmen Square and intimidating journalists or their sources.
The country's communist leadership sent soldiers to forcibly clear the square and surrounding areas on the night of June 3-4, 1989, ending seven weeks of protests calling for political reforms.
Hundreds, possibly thousands, were killed in the crackdown, which remains a taboo subject in China.
(c) 2009 AFP
Explore further: Google chided for China censorship deal