Gmail is starting to see life again in China.

Google's e-mail service has seen a slight uptick in traffic going into the country, according to the company's Transparency Report. The Financial Times (subscription required) was the first to notice that access had returned.

The increase hints at the end of a four-day outage in China, one with no explanation. Greatfire.org, a China-based anticensorship group, suggested the country may have been responsible, Reuters reported.

Google told CNET in an e-mail that there was nothing on its end that caused the outage, while a Chinese Foreign Ministry spokeswoman told Reuters that she wasn't aware of an issue.

A spokesman from the Consulate General of China's office in New York couldn't be reached for comment about the outage.

Google has had problems operating in China for years, and the country blocked Gmail access to its browsers in June ahead of the 25th anniversary of the Tiananmen Square massacre. A loophole that allowed users to access Gmail through Microsoft's Outlook or Apple's email client had been closed over the past four days. That loophole has once again opened.