NEW YORK (AP) - AT&T says its service is running normally after a "hardware issue" prevented some customers' phone calls from connecting.

In a short statement, the Dallas, Texas, company apologized for the inconvenience caused during "a brief period" Saturday morning. The company did not provide any other details or say how many people were affected.

Earlier Saturday, some people had posted on Twitter that they were AT&T customers and were unable to make or receive calls.

The comments on the company's outage website included posts from Minnesotans saying they had lost service. Brooks Johnson in Nisswa said, "I just tried the 'airplane mode' by turning it on and then off. Now I have phone service!"

This follows Wednesday night's loss of 911 service for some AT&T customers in at least 14 states and Washington, D.C.

In that case, the telecommunications giant also did not say when the problem began or how many customers were affected.

Verizon and AT&T are the largest wireless carriers in the United States.