Facebook endures hours-long outage in the U.S.

Many Facebook users in the U.S. are apparently having a hard time getting onto the social network.

Twitter is abuzz with user comments that Facebook isn't working for them. And, the site downforeveryoneorjustme.com is also reporting the social network is down. According to The Next Web, users from Texas to New York have complained of intermittent access. Many users have not been affected by the outage, however.

While the site is down for many people, mobile notifications seem to be working, as is the mobile site m.facebook.com.

Facebook has had outages here and there over the last few years. In December, the social network suffered a DNS issue that caused some people temporarily being unable to reach the site. And in October, the company inadvertently caused many users across Europe to be knocked off the site after problems with traffic optimization tests.

It's unclear what exactly is causing the outage now. Web site monitoring service downrightnow.com is currently reporting Facebook's status as "Likely Service Disruption," and at the time of this writing it suggests that the site has had intermittent access for the last three hours.

Updated at 9:25 p.m. PT with comment from a Facebook spokesperson:

"Earlier today we experienced a DNS issue that briefly prevented people who typed 'facebook.com' into their browsers from reaching the site. People who accessed the site using a mobile app, typed 'www.facebook.com' into their browsers, or used a bookmark or a search engine to navigate to the site were not affected. We resolved the issue quickly, and the fix should be fully propagated now. We apologize for any inconvenience."