OLYMPIA, Wash. – Five children in Western Washington are in the hospital with a mysterious polio-like illness that causes paralysis in arms and legs.

The Washington State Department of Health said Wednesday it was investigating the cases of possible acute flaccid myelitis.

All of the cases involve infants or children under the age of six.

Officials said all of them had symptoms of a respiratory illness the week before they developed symptoms of AFM. And four of the children had a fever of at least 100.4 degrees.

Two cases were reported in King County and one each in Pierce, Lewis and Snohomish counties.

The Department of Health is working with the Centers for Disease Control and Prevention to confirm if the children have AFM.

“At this point, there isn’t evidence that would point to a single source of illness among these cases,” said Dr. Scott Lindquist, state infectious disease epidemiologist at the Department of Health. “We’re working closely with medical providers and public health agencies. We’ll continue to investigate and share information when we have it.”

The Department of Health issued the health notice on Wednesday: