The secret network included "several democracies in Eastern Europe" as well as Thailand and Afghanistan, the newspaper reported, but it did not publish the names of the European countries at the request of senior US officials.
US government officials declined comment on the report. Russia and Bulgaria immediately denied any facility was there. Thailand also denied it was host to such a facility.
US national security adviser Stephen Hadley would not comment directly, but said President George W. Bush had made clear the United States fought terrorism while respecting the law, and investigated allegations of misconduct.
"While we have to do what is necessary to defend the country against terrorists and to win the war on terror, the president has been very clear that we're going to do that in a way that is consistent with our values and that is why he has been very clear that the United States will not torture," Hadley said.
The newspaper, which said its report was based on information from US and foreign officials familiar with the arrangement, said the existence and locations of the facilities were known only to a handful of American officials and, usually, only to the president and a few top intelligence officers in each host country.
