Chinese authorities appear to have blocked access to Google’s Gmail service in the country, according to several reports. The latest outage, which affects users’ ability to access Gmail through third-party clients such as Apple Mail and Microsoft Outlook, comes after months of the Internet giant having parts of it services blocked in the Middle Kingdom’s Great Firewall.

Chinese authorities earlier this year blocked access to Gmail and other Google websites around the 25th anniversary of the June 4, 1989 Tiananmen Square protests and massacre.

Data from Google shows traffic to Gmail dropping to zero from Chinese servers.

Google has been on the radar of Chinese authorities for years, and has previously been asked to censor its search results.

Chinese users still hoping to access their Gmail accounts will now have to go through virtual private networks, or VPNs, to bypass the block.