Google is accusing the Chinese government of interfering with the operations of the company's popular Gmail service.

Gmail customers in China have complained during the past month of experiencing problems with the e-mail service, including difficulty sending e-mails and marking them as unread, in addition to other issues, according to a story first reported by The Guardian newspaper.

"There is no issue on our side' we have checked extensively," a Google spokesperson told CNET. "This is a government blockage carefully designed to look like the problem is with Gmail."

The revelation follows a March 11 Google on Security blog post in which Google said it had "noticed some highly targeted and apparently politically motivated attacks against our users. We believe activists may have been a specific target." That post referred to a critical Windows MHTML vulnerability that Microsoft revealed in January that allowed hackers and other third parties that exploit the vulnerability to gain access to a user's information.

Tensions between China and the search giant have been smoldering since Google disclosed the theft of intellectual property in January 2010, revealing that it and other companies were the victims of a "highly sophisticated and targeted attack" aimed at gathering information about human rights activists. For its part, the Chinese government has denied any involvement.

As a result, Google said it no longer intended to filter search results and publicly declared its intention last March to move its Chinese-language Internet search operation in Hong Kong in hopes of bypassing censorship laws for companies that operate in mainland China.

Last June, Google revealed that its users inside of China were unable to use Google's search suggestions feature, but the search giant did not at the time blame the Chinese government for the blockage. The next month, the Chinese government renewed Google's license to continue running its Web site in China.