The Minnesota Hospital Association and the state's Attorney General's Office are warning that scammers are posing as health care representatives and attempting to obtain customers' financial information.

Both agencies issued the warning following last month's cyberattack against Change Healthcare, which is a subsidiary of UnitedHealth Group and one of the largest health care payment systems in the country that handles billions of transactions annually.

Since the Feb. 21 breech, patients have reported getting calls from scammers claiming to be representatives from hospitals, clinics and pharmacies offering refunds or demanding payment. The callers ask the patient to provide their credit card numbers, banking or other financial information.

"Your hospital will not call or email you to ask for a credit card number," said Lou Ann Olson with the Minnesota Hospital Association in a video posted Sunday on social media. "Exercise caution in every interaction about your health affairs."

The association urges anybody who receives a solicitation by telephone, email or mail to not respond and instead contact their health care provider directly.

Attorney General Keith Ellison asked anybody who receives one of the suspicious calls in which they are asked for payment to terminate it immediately, then call their health care provider and report it to his office at 651-296-3353 in the metro area and 1-800-657-3787 elsewhere in Minnesota.

"Remember, these scammers make a living by tricking people," Ellison said. "They are sophisticated, experienced and persuasive, so be on your guard."

UnitedHealth Group said its electronic medical payments and pharmacy services were back online last week and that it plans to test and re-establish connection to its medical claims network this week.