HOPKINS, Minn. -

Minnesota health officials are investigating several possible sources of an outbreak of Legionnaires' disease in the Minneapolis suburb of Hopkins.

Minnesota Department of Health officials confirmed with Fox 9 on Friday that there are now 9 confirmed cases of Legionnaires' disease in Hopkins. That number is up from just Wednesday when there were only 6 confirmed cases.

The confirmed cases involve people ranging in age anywhere from in their 20s to 90s. Currently, there are no deaths to date, but most were hospitalized and some remain hospitalized at this time.

Officials say cooling units on large buildings can be a source of the disease. Investigators are currently looking at SuperValu, Thermal Tech, a fountain at Cargill, and other small buildings in the area.

Legionnaires' can cause pneumonia-like symptoms, including cough, shortness of breath, muscle aches, headaches, and fever. The disease is not spread person to person.

More than 60 cases have been reported in Minnesota so far this year.