Facebook said late Tuesday that it was not aware of any blocking of its sites in China, despite reports of outages from cities around China.

"We are disappointed to learn of reports that users in China are having difficulty getting access to Facebook. We have not made any changes to our site that would create access problems and are looking into the situation," a Facebook spokesperson said in an e-mail response to a request for comment.

Attempts to reach Facebook by IDG News Service in Beijing on Tuesday and Wednesday sometimes successfully loaded its main login page.

Other tries received "The server at www.facebook.com is taking too long to respond," a common response during periods of heavy traffic, but also the result that users accessing blocked sites receive. As of this writing the site could be accessed from Beijing by IDG News Service.

Media and technology blogger Will Moss reported no interruptions Tuesday or Wednesday. In Shanghai, business owner Maria Trombly said Facebook was available there Wednesday morning local time.

Facebook launched its Chinese site almost two weeks ago, into a market that has not fallen in love with social networking sites the same way that many Western countries have.

China blocks sites displaying material that censors deem objectionable, including pornography and politically-sensitive news and views counter to the government's official positions. This year, YouTube, Wikipedia's English-language site and Blogspot have all been blocked for periods. Wikipedia's Chinese-language sites remain blocked.