A human error may be to blame for China’s major internet outage on Tuesday.

According to Reuters, human error was likely to blame for a glitch in China's Great Firewall.

CNN reported that millions of China’s internet users were affected and blocked from certain sites, while others were rerouted to a homepage of a U.S. company with ties to a group outlawed in the country.

Web users had trouble accessing numerous sites for about an hour and some traffic was sent to the Dynamic Internet Technology page. DIT has since denied any involvement or knowledge of the malfunction at that time.

China closely monitors the internet use of its residents.

“Their DNS hijacking system is used to redirect visits to certain websites to the wrong IP address," said DIT’s President Bill Xia. “But this time it was likely a temporary misconfiguration that affected all domain names.”

Analysts first believed that the problem was the work of hackers, but those claims were debunked after technical testing showed that it would not have been enough to cause such an outage.