(CNN)A hotline set up to help people in Pennsylvania's Allegheny County schedule Covid-19 vaccination appointments was partially compromised, county officials said.
The service opened at noon on Thursday to help residents 65 and older who lack internet access or need additional assistance, CNN affiliate KDKA reported. The county is home to Pittsburgh, the second-most populous city in the state.
At some point "mid-afternoon," the county health department and the 2-1-1 service became aware that a hacker was intercepting callers and diverting them away from the helpline without their knowledge, according to a news release from the county.
"While 2-1-1 is continuing to work with its telephone partners to investigate this, we do not know which carrier was involved or how many callers this impacted," the release said. "The problem was quickly identified and resolved."
Some residents told KDKA that when they called, the person on the other end of the line asked them for credit card information. Allegheny County would not confirm the nature of the alleged hacker's calls, but directed callers to contact the FBI if they believe their calls were intercepted.
"A 2-1-1 Resource Navigator will never ask for personal financial information like credit card numbers or ask for a person to purchase or send a gift card before being able to make an appointment," the release said.
The FBI would not confirm or deny the existence of an investigation.
CNN has also contacted the Allegheny County police for comment.
How to protect yourself from scams
As the Covid-19 vaccine becomes more widely available, fraudsters are inevitably taking advantage of the situation -- putting people at risk of having their personal information exposed and money stolen without ever getting a shot.
Staying vigilant and informed is the best way to prevent scammers from accessing your money or private information.
If you're sent communication about vaccines that seems suspicious, check it out with your local health department. Don't share personal information such as your credit card number or Social Security number with someone you don't know, unless you've verified their identity with an official source such as your health department or health care provider. And only take the vaccination at authorized vaccination sites.
You can report vaccine scams at these places: