Users may be having trouble accessing Facebook due to a problem the site is having with a network provider, the company said. "Some people can't connect to Facebook because of an issue with a third-party network provider. We're working to fix it ASAP," Facebook wrote in a Twitter message around noon Pacific Time.

That message followed user complaints that started popping up on Twitter earlier in the day.

Facebook did not respond to a request for details about the issue or about how many people have been affected. In a statement, it said it is in contact with the network provider "to explore what can be done to resolve the issue." Facebook also said it is working on ways to bypass the affected connections.

Facebook seems to have less frequent outages than Twitter, a rival in social networking. However, it had one notable failure last year, when around 150,000 people were unable to use the site for more than a week.