Comcast's Xfinity internet service is suffering major issues on Monday, the company confirmed.
Consumers in several US cities, including San Francisco, Chicago, Seattle and New York, have reported outages, according to the website Down Detector. The site says 66 percent of the reports are about issues with internet service.
Comcast said it's working to fix the problem.
"Some customers are having issues with their XFINITY Internet service," the company tweeted. "We apologize & appreciate your patience while we work to fix."
Comcast also said the problem may come from an "external network issue." Comcast didn't immediately respond to a request for additional comment.