Verizon customers across the United States, including Seattle and King County, are reporting outages in service, according to the service tracking website Down Detector.

Down Detector has received more than 20,000 reports of Verizon outages on Wednesday with 3,500 reports coming from Seattle around 3 p.m. Customers in locations including Los Angeles, Sacramento, Spokane, Phoenix and other cities also reported outages.

A spokesperson for Verizon told the fact-checking website Snopes that the company is “aware of an issue impacting voice calls for some Verizon customers” and is working to solve the problem.

King County advised anyone affected by the outage experiencing an emergency to use the county’s text to 911 service or call 911 with a landline or phone with another carrier.

“Please do not call or text 9-1-1 to test the system,” the county said on Twitter.