MONTGOMERY COUNTY, Pa. (CBS) — AT&T officials confirm 911 service for their wireless customers has been restored nationwide after being down for several hours Wednesday evening.

Various law enforcement and government agencies around the U.S. reported that AT&T customers were unable to call 911 from their cellphones.

The Montgomery County Department of Public Safety Twitter account tweeted Wednesday evening calls made by AT&T customers were not getting through.

AT&T users in Montgomery County, Chester County, Bucks County and Delaware reported outages.

The Ogden Fire Company in Delaware County also said they had issues making emergency calls.

The outages were also reported in other parts of the nation, including DC and parts of Texas.

A spokesman for AT&T told CBS 3 Wednesday evening the company was aware of service issues affecting some calls to 911 for wireless customers.

“We are aware of a service issue affecting some calls to 911 for wireless customers and we’re working to resolve it as quickly as possible.  We apologize for this inconvenience,” said Brandy Bell-Truskey with AT&T Global Media Relations.

It remains unclear how many states were affected by the outage. The representative did not say what caused the outage.