China suffered a major Internet outage yesterday, which is said to have knocked out access to two-thirds of the .com domain websites in the country.

An unidentified issue caused a large number of websites to be unreachable for at least one hour. During that period, Internet users were redirected to a website owned by Dynamic Internet Technology, a company that works with the Falun Gong, a Buddhist group that — among other things — offers VPN software to counteract China’s Internet censorship.

Dynamic Internet Technology president Bill Xia told South China Morning Post he believes the incident was a result of a system malfunction or operator mistake which redirected a range of Internet domains to the company’s site, which is actually banned in China. The surge in traffic triggered Dynamic Internet Technology’s security system to shut down the site to many, leaving them with blank pages.

The incident is said to have affected users for an hour, but the issue was reported to be longer lasting in rural areas. A representative from Net.cn, an Internet service provider owned by Alibaba, told SCMP that the incident unprecedented. China experienced a notable outage in 2012, which saw Sina Weibo go down on the first day of a murder trial involving a high-profile politician’s wife.

There was some debate on whether sites were actually down, however. Some China-based Internet users who use VPNs to access the Web unfiltered, found no noticeable issues accessing sites.

IT performance company Compuware told TNW that the issue was seemingly related to DNS, which could explain why VPN users were unaffected even after disabling their software. A spokesperson from the company said the outage continued to affect millions of users for up to eight hours, due to caching issues.

Update: Reuters reports that Chinese Foreign Ministry spokesman Qin Gang said the incident “again shows that China is a victim of hacking”, although China Web monitoring organization GreatFire.org refuted the suggestion that hackers were responsible:

Many Chinese media stated that yesterday’s outage may have been due to a hacking attempt. The IP is operated by Dynamic Internet Technology, “mortal enemy number one” of the Chinese government. Some are suggesting Dynamic Internet Technology is behind the outage. However, hacking into a root DNS resolver is not enough to cause this outage, as we explained earlier in this post. They have to hack into GFW. If they are indeed capable of doing that, they can accomplish so much more than messing the entire Chinese internet up.

Related: China now wants Internet users who upload videos to provide their real names

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