"Our engineers worked to address the issue immediately and services are now being restored to business and residential internet, video and voice customers," the company said in a statement.

Comcast said the two network providers were CenturyLink Inc and Zayo Group Holdings Inc.

"While the CenturyLink network continues to operate normally, on June 29, we experienced two isolated fiber cuts in North Carolina affecting some customers that by themselves did not cause the issues experienced by other providers," CenturyLink said.

Zayo officials were not immediately available for comment.

Comcast had 22.4 million video customers, 25.9 million high-speed internet customers and 11.6 million voice customers as of Dec. 31, 2017, according to its latest annual filing.

(Reporting by Arunima Banerjee in Bengaluru; Editing by Dan Grebler)