BEIJING Some International Olympic Committee officials cut a deal to let China block sensitive websites despite promises of unrestricted access, a senior IOC official admitted on Wednesday.
Persistent pollution fears and China's concerns about security in Tibet also remained problems for organizers nine days before the Games begin.
China had committed to providing media with the same freedom to report on the Games as they enjoyed at previous Olympics, but journalists have this week complained of finding access to sites deemed sensitive to its communist leadership blocked.
"I regret that it now appears BOCOG has announced that there will be limitations on website access during Games time," IOC press chief Kevan Gosper said, referring to Beijing's Olympic organizers.
"I also now understand that some IOC officials negotiated with the Chinese that some sensitive sites would be blocked on the basis they were not considered Games related," he said.
Attempts at the main press centre to access the website of Amnesty International, which released a report on Monday slamming China for failing to honor its Olympic human rights pledges, continued to prove fruitless by mid-week.
Other websites, including those relating to the banned spiritual group Falun Gong, are also inaccessible.
Beijing organizers said censorship would not stop journalists doing their jobs in reporting the Games.
"We are going to do our best to facilitate the foreign media to do their reporting work through the Internet," BOCOG spokesman Sun Weide told a news conference.
"I would remind you that Falun Gong is an evil, fake religion which has been banned by the Chinese government."
Reporters without Borders, a Paris-based media watchdog, said it was increasingly concerned that there would be many cases of censorship during the Olympics.
"We condemn the IOC's failure to do anything about this, and we are more skeptical about its ability to ensure that the media are able to report freely," the group said in a statement.
But the admission that the Internet will be partly censored is sure to lead to more criticism for the Olympics host nation, which is already deflecting barbs over everything from the quality of its air to its human rights record.
On Wednesday, Chinese experts said they were working on emergency plans to keep Olympic skies clear, including keeping cars off the roads in nearby provinces, but expected not to need them unless unusual pollution-trapping weather continued.
The city has already banned cars from roads on alternate days under an odd-and-even license plate scheme, suspended some factory production and opened new subway lines to try to clear its notorious pollution.
"The likelihood of needing stronger measures is very small," said Zhu Tong, a professor at Peking University and leader of a technical group advising Games organizers on air quality.
Slightly cooler temperatures and rain on Tuesday have thinned the haze, but with below-par air quality readings on several days since the emergency measures took effect on July 20, worries remain about athletes wheezing air laced with fumes and dust.
Experts said that given the size of Beijing, the volume of pollutants that flow into the city from other parts of China, and the short time period before the Games open on August 8, there was little more that could be done.
"In this short a time-frame, even if you took all the personal cars off the highway, you might see another 10 percent improvement, but it would be small," said Staci Simonich, an analytical chemist at Oregon State University who has been studying Beijing's air quality.
"The best thing that could happen during the Games is to have it rain every night," she said.
China also has other issues on its mind, including security in the restive region of Tibet, where official media said Chinese police had been mobilized to ensure "absolute security without a single lapse".
The remote region erupted into rioting in March that sparked protests across China's ethnic Tibetan areas and brought into focus international criticism of Beijing's policies on the issue.
The Tibet Daily announced on Wednesday tough policing during the Games on top of a sweeping security crackdown already in place. China is at pains to avoid any shows of defiance by pro-Tibet independence groups that could embarrass the government before a worldwide audience.
(Additional reporting by Emma Graham-Harrison, Lindsay Beck, Chris Buckley, Liu Zhen and Simon Rabinovitch; Writing by Lindsay Beck; Editing by Sanjeev Miglani)
(For more stories visit our multimedia website "Road to Beijing" here)