PARIS - Press rights group Reporters Without Borders said that a "paranoid" China had blocked tens of thousands of websites ahead of the 60th anniversary of the People's Republic.

The Paris-based group said that Chinese authorities had targeted Virtual Private Networks (VPNs) and other ways that residents, including foreign reporters, used to circumvent controls on the Internet.

The group said that "government security paranoia" in the run-up to Thursday's anniversary was "turning into a major headache for Internet users and reporters."

It estimated that tens of thousands of web addresses had become inaccessible in recent days and said it was even more difficult to reach Facebook, Twitter and other social networking and blogging sites that were already blocked.

"The Electronic Great Wall has never been as consolidated as it is now, on the eve of the October 1 anniversary, proving that the Chinese government is not so sure of its record," the group said.

It said that authorities particularly clamped down on websites linked to ethnic minorities in Xinjiang and Inner Mongolia. Xinjiang in July saw China's deadliest ethnic unrest in decades that pitted the majority Uighur population against the nation's predominant Han ethnicity.

China's military plans a show of force on Thursday and is likely to parade its new intercontinental ballistic missiles as the Communist Party highlights the nation's transformation into a world power.