Customers of wireless provider T-Mobile US Inc. reported widespread service outages in the U.S. late Monday, according to websites tracking service interruptions.

Posts on Downdetector.com and Product-Reviews.net indicated T-Mobile service outages in multiple areas of the country. Many Twitter users also reported outages.

Numerous posts by users said their service had been changed to “SOS mode,” meaning they were not directly connected to a network but could still make emergency calls.

T-Mobile President of Technology Neville Ray issued a statement about the outage on Twitter early Tuesday.

“We have seen significant improvement and are operating at near normal levels," Ray said. "Our teams continue to monitor and we greatly appreciate everyone’s patience. We apologize for any impacts this issue may have had for our customers.”

The company did not immediately provide details of the cause or extent of the outage.

Downdetector.com provided a chart tracking service complaints within the previous 24 hours indicating a peak of more than 69,000 reported outages in a two-hour period.

Posted comments on the site came from users who said they were located in Arizona, California, Colorado, Florida, Hawaii, Kansas, Nebraska, North Carolina, Oklahoma, Texas and Washington.

Similar service complaints on Product-Reviews.net originated from some of the same states, as well as Alabama, Connecticut, Idaho, Minnesota, New York, Nevada, South Carolina and others.

Many posts reported service eventually was restored.