BISMARCK, N.D. (AP) — North Dakota’s Health Department has issued a blue-green algae advisory for three more lakes in the state, bringing the total to six.

Advisories have now been issued for Homme Dam in Walsh County, Sweet Briar Dam in Morton County and Lake LaMoure in LaMoure County.

Advisories previously were issued for Camels Hump Dam in Golden Valley County, Green Lake in McIntosh County and Long Lake National Wildlife Refuge in Burleigh County.

Blue-green algae blooms when the water is warm, slow-moving and abundant with nutrients. The algae can produce toxins that can cause severe diarrhea, vomiting, numbness, rashes and even death.

The advisories don’t prohibit the use of the lakes, but people are advised to avoid the algae. Pets and livestock shouldn’t drink affected water.