Many Gmail users in China are experiencing a major setback as they have been unable to access their email accounts since last week. GreatFire.org, a freedom of speech advocacy group based in the country, said the service went down on Friday and Gmail users still couldn't access their accounts on Monday. Google has echoed this remark, saying that based on their Transparency Report, there has been a significant drop in Gmail traffic in China last Friday.

"We've checked and there's nothing wrong on our end," a Google representative said.

This follows the disruption of Google services in the country since June, and anti-censorship advocacy groups deem that this is due to the government's tight rein on the Internet.

"I think the government is just trying to further eliminate Google's presence in China and even weaken its market overseas," said a member of GreatFire, as quoted by Reuters.

The group also said that this disruption would pose difficulty for companies who use email as a means of communication.

"We encourage China to be transparent in its dealings with international companies and to consider the market signal it sends with such acts," said Jeff Rathke, a representative for the U.S. State Department.

Hua Chunying, a spokesperson for the Chinese Foreign Ministry, however, denied any knowledge about Google's email service being blocked in the country.

New York Times quotes her as saying, "China has consistently had a welcoming and supportive attitude toward foreign investors doing legitimate business here. We will, as always, provide an open, transparent and good environment for foreign companies in China."

Reuters explains that the Chinese government maintains strict control over Internet use in the territory, facilitating what is commonly called the Great Firewall of China, deemed as "the world's most sophisticated Internet censorship mechanism." It restricts and censors anything that might challenge the currently ruling Communist Party, or what it considers as offensive or a threat. Facebook, Instagram, Twitter, YouTube, New York Times, and Bloomberg News are among the popular sites blocked in the country.