Olympic organizers are backtracking on another promise about coverage of the Beijing Games, keeping in place blocks on Internet sites in the Main Press Center and venues where reporters will work.

The blocked sites will make it difficult for journalists to retrieve information, particularly on political and human rights stories the government dislikes. On Tuesday, sites such as Amnesty International or any search for a site with Tibet in the address could not be opened at the Main Press Center, which will house about 5,000 print journalists when the games open Aug. 8.

“This type of censorship would have been unthinkable in Athens, but China seems to have more formalities,” said Mihai Mironica, a journalist with ProTV in Romania. “If journalists cannot fully access the Internet here, it will definitely be a problem.”