News: The outage stemmed from its transit provider Telia.
The outage has led users to take to social networking site Twitter to express their anger, reporting non-availability of access to sites like Medium, Intercom, and Slack.
Responding to the users’ problems, the company said: "CloudFlare is observing network performance issues in some European locations. We are actively working to reduce or eliminate any impact to Internet users in this region."
The company said that it has identified the issue and a fix has been implemented.
CloudFlare found that the outage has been caused by Telia Carrier, a Swedish network provider that operates underwater cables to link internet services across the globe.
In a blog post, CloudFlare said: "On June 17, at 08:32 UTC, our systems detected a significant packet loss between multiple destinations on one of our major transit provider backbone networks, Telia Carrier.
"Typically, transit providers are very reliable and transport all of our packets from one point of the globe to the other without loss – that’s what we pay them for. In this case, our packets (and that of other Telia customers), were being dropped."
"A fix has been implemented and we are monitoring the results. This incident has been resolved."
It said that there was a sharp increase in 522s errors to over 800,000 when the outage occurred, indicating that its servers failed to access the origin servers of our customers.
The San Francisco-headquartered firm was able to shift traffic away from Telia to other Tier 1 providers after identifying the problem. It has partnered with many Tier 1 providers in Europe.
CloudFlare added: "In today’s incident, we identified weaknesses in our communication: the scope of the incident was incorrectly identified in Europe only, and our response time was not adequate."
CloudFlare said that it taking steps to improve its communication, including implementation of automated detection and mitigation systems that can react much more quickly than any human operator.
The company is also rushing a fix to restore its network performance in Los Angeles after observing a disruption.