"We understand there are reports of users being unable to access YouTube within the People's Republic of China," the spokesperson said in an e-mailed statement. "We are looking into the matter and working to ensure that the service is restored as soon as possible."
The spokesperson offered no explanation as to why the video-sharing site had become inaccessible, but a BBC news report indicates that Chinese authorities blocked access to YouTube because it hosted videos of Chinese soldiers beating monks and other Tibetans.
A Chinese government spokesman told the BBC that China is not afraid of the Internet, but declined to confirm whether YouTube had been blocked.
The Chinese government has been anxious to avoid a repeat of last year's riots in Tibet, particularly on March 10, which marked the 50th anniversary of the failed Tibetan uprising against Chinese rule, which forced the Dalai Lama to flee the country.
Last year, during the March riots in the Tibetan capital of Lhasa, China blocked access to YouTube.
At the time, YouTube offered the very same statement it offered this year: "We understand there are reports of users being unable to access YouTube within the People's Republic of China. We are looking into the matter and working to ensure that the service is restored as soon as possible."
On March 9, Reporters Without Borders expressed outrage at "the systematic violation of press freedom and free expression in Tibet." It urged China to allow foreign journalists to freely visit Tibet, to grant Tibetan media more free expression, and to stop jamming international radio stations broadcasting in the Tibetan language.
The press freedom group said that the Internet in Tibet slowed as the March 10 anniversary approached.
YouTube has been blocked by other countries, including Burma, Brazil, Iran, Morocco, Pakistan, Thailand, and Turkey.