(KLZA)--The state of Nebraska has issued a health alert for Iron Horse Trail Lake in Pawnee County due to the presence of blue-green algae.

According to a release Thursday, samples taken earlier this week from the lake indicated that the toxin level given off by the algae was higher than normal.

Signs have been posted to advise the public to use caution, and designated swimming beaches are closed during the alert.

Recreational boating and fishing are permitted, but the public is advised to use caution and avoid exposure to the water, particularly by avoiding any activity that could lead to swallowing the water.

Do not let pets get in the water or drink from the lake.

People can still use the public areas for camping, picnics, and other outdoor activities.