RALEIGH, N.C. (AP) — Officials in North Carolina are warning residents to avoid contact with green or blue water in the Chowan River because of an algal bloom.

The N.C. Division of Water Resources said in a news release that the affected areas include Bertie and Chowan counties. Reports indicate the bloom has appeared along the eastern and western shorelines of the river from Harrellsville downstream to the Edenton Bay area, as well as the Colerain and Rockyhock areas.

So far, there have been no reports of health problems associated with the bloom.

Algal blooms of this type usually appear bright green, but when a bloom starts to decay, the color can change to a milky blue. The decaying algae produces a strong, foul odor that can impact a large area.