In the run-up to the 20th anniversary of the Tiananmen Square massacre, China is censoring foreign media and the internet to an extent not seen since the crackdown that preceded the Beijing Olympics.

Government agencies are banning delivery of foreign newspapers, disrupting satellite news broadcasts and blocking internet sites including Twitter and Hotmail in a campaign apparently aimed at extinguishing every reference to the 1989 pro-democracy student movement, which the People's Liberation Army suppressed on June 4 of that year.

BBC News broadcasts were blacked out in Beijing on Monday night. Last Saturday's edition of the Financial Times, which contained an interview with Bao Tong, the most prominent Tiananmen-era dissident still residing in China, was either not delivered to subscribers or censored. Copies of the International Herald Tribune and Hong Kong's South China Morning Post, which has dedicated extensive coverage to the anniversary, have been shredded. The government has censored Tiananmen- related stories on www.ft chinese.com, the FT's Chinese language website.

Most of the information plaguing censors is flowing in from Hong Kong, one of only two Chinese special administrative regions where freedom of press and assembly is still respected.

In contrast to the state-enforced amnesia in China, civic organisations in Hong Kong are marking the anniversary with marches, speeches, art shows and rallies, which will culminate in a vigil tomorrow night. “There is still sufficient room for us to fight for a more democratic system [in Hong Kong],” Albert Ho, chairman of the territory's Democratic party, told an academic conference.