INDIANAPOLIS (AP): State officials have lifted a moratorium on feeding birds in 76 Indiana counties as an investigation continues into how songbirds are dying.

But people in Allen, Carroll, Clark, Floyd, Hamilton, Hancock, Hendricks, Johnson, Lake, Marion, Monroe, Morgan, Porter, St. Joseph, Tippecanoe, and Whitley counties still should not feed birds, the Indiana Department of Natural Resources said Monday.

The moratorium was recommended June 25 “to slow the spread of a still-undetermined illness that is killing birds across the state,” the DNR said in a release.

“Based on the data, it appears that the bird illness is consistently affecting specific areas,” the DNR said. “There is no imminent threat to people, the population of specific bird species, or to the overall population of birds in Indiana.”

Wildlife managers and veterinarians first received reports in late April and May of sick birds in Maryland, Virginia, West Virginia, Kentucky, and Washington, D.C. In addition to Indiana, other reports have come from Pennsylvania, Delaware, New Jersey, and Ohio.

In Indiana, the sick songbirds were initially found in late May in southern Indiana’s Monroe County.

The main visible symptoms are swollen eyes or crusty discharge around the eyes, as well as off-balance movements that may indicate neurological damage.

The majority of birds reported as ailing have been fledgling blue jays, American robins, European starlings, and common grackles, but other songbirds are also affected.

The U.S. Geological Survey, which oversees responses to some natural hazards and risks, recommended that people temporarily take down bird feeders and clean out birdbaths to reduce places that birds could closely congregate and potentially spread disease.