Beijing Olympics organizers, who had so far carefully navigated questions that "politicize" the Games, hit out at "lies" about the state of the Muslim Uyghur minority in Xinjiang and reiterated the government's stance on Taiwan on Thursday.

The U.S. has led a diplomatic boycott by some Western nations at the Games over rights concerns in China, especially the fate of the Uyghurs in northwestern China's Xinjiang.

Rights issues overshadowed the build-up to the Olympics in the Chinese capital and they roared back to the fore during a regular daily press conference featuring an IOC spokesman and officials from the local organizing committee.

Campaigners say that at least 1 million Uyghurs and other Turkic-speaking Muslims have been incarcerated in camps in Xinjiang, while there are also allegations of forced sterilizations of women and forced labor.

"These issues are irrelevant to the Winter Games but I still feel obliged to make a quick comment again," said Beijing 2022 Organising Committee spokeswoman Yan Jiarong, after foreign reporters twice asked about Xinjiang.

"The questions are based very much on lies. Some authorities have already disputed such false information with a lot of solid evidence."

Yan also criticized what she called "lies by deliberate groups" over Xinjiang.

China vehemently denies all charges over its treatment of Uyghurs and maintains the camps are vocational training centers aimed at reducing the appeal of "Islamic extremism."

Yan was also bullish on the question of Taiwan. China claims the self-ruled democratic island as part of its territory to be retaken one day, by force if necessary.

At all Olympic Games, athletes from Taiwan compete under the banner of "Chinese Taipei."

"This is something that we really have to take a solemn position on," said Yan, following a question about Taiwanese athletes at the Games and their attendance at Sunday's closing ceremony.

"What I want to say is that there is only one China in the world.

"Taiwan is an indivisible part of China and this is a well-recognized international principle and well recognized in the international community.

"We are always against the idea of politicizing the Olympic Games."