Google (GOOG.NASDAQ) reported an unusual decline in traffic on its China sites, as an internet monitor said its services were being blocked in the country, Bloomberg reported. Google’s Transparency Report, which measures traffic to its sites around the world, on Saturday showed an unusually large slump in visits to its China sites, while Greatfire.org, a website that monitors internet activity and access in China, reported that the company’s services including mail, maps and document storage were being blocked. China’s government, which is currently holding its 18th Communist Party Congress, adamantly blocks websites that are seen as not complying with the country’s strict media restrictions. Google refused to comply with censorship restrictions in 2010, when it shut down its local search page and began redirecting users to a Hong Kong site.