Attempts to access the Guardian website have been blocked on multiple devices across Beijing from this Tuesday, according to anti-censorship company greatfire.org.
A Guardian News & Media spokesperson said, "Obviously we are dismayed that theguardian.com has been blocked in China. The reason for this is currently unclear but we are investigating the extent of the block and hope that access to our website will return to normal in the very near future."
Chinese PC users commenting on the Guardian website have reported unreliable access, while the newspaper's mobile and iPad apps have so far remained unaffected.
Chinese leaders have censored Western newspapers in the past. The New York Times has been blocked for over a year after it released investigations detailing the wealth of Chinese leader's families.
But the rationale for the alleged blocks are not certain, nor is their likely duration. "No China-related stories published by the Guardian in the past two days would obviously be perceived as dangerous by the country's leadership," the newspaper said in an article on its website.
A Guardian report which ran on January 6 explored political tensions in China's ethnically diverse northwestern region of Xinjiang, but previous coverage of this issue has not generated fallout according to the newspaper.
At a press briefing on Wednesday Chinese foreign ministry spokeswoman Hua Chunying said, "This is the first time I have heard of this,” according to Reuters. "I don't understand the situation. You can inquire with China's relevant department."
The news occurs as Guardian News & Media (GNM) is set to launch lifestyle supplement for the Saturday edition of the Guardian: Do Something. The monthly magazine, which will appear for the first time of Saturday 11 January, will offer expert advice and guidance to encourage readers to gain new skills and experiences.