Some Verizon customers were experiencing a service outage on Wednesday afternoon, according to the company.

Verizon said it was not immediately clear how long the service would be down.

“We are aware of an issue impacting wireless voice and data services for some customers,” Verizon said in a statement to ABC News. “Our engineers are engaged and are working to identify and solve the issue quickly. We understand how important reliable connectivity is and apologize for the inconvenience.”

Many Verizon customers said on social media that their phones showed “SOS” in place of network bars.

According to Downdetector at least 175,000 Verizon customers were affected at one point, but that number has since gone down. Downdetector, a site that tracks outages, said Verizon customers began noticing interrupted service around noon Eastern time.

New York Emergency Management (NYCEM) officials said the outage is affecting some users calling 911.

“Verizon is working to solve the issue,” NYCEM said in a statement. “If you have an emergency and cannot connect using your Verizon Wireless device, please call using a device from another carrier, a landline, or go to a police precinct or fire station to report the emergency. In the meantime, you can check the website or social media account of your cellphone carrier for updates.”

This is a developing story. Please check back for updates.