The N.S. Environment Department is warning people in Inverness County not to drink water from some local lakes and rivers while they investigate reports of an algae bloom.

The department said Wednesday that a bloom in Lake Ainslie may also be in the Southwest Margaree River and the Margaree River, in the same county.

In a release, the department said that toxins produced by some algae can have negative effects on health and warned residents not to drink the water or use it to cook food or brush teeth.

"Boiling the water will not eliminate potential toxins," said Dr. Richard Gould, medical health officer for the region.

He said ingesting water containing toxins can cause stomach aches, diarrhea, vomiting and nausea.

Gould also cautioned against pets and livestock swimming in or drinking the water.

He said people should also avoid consuming the internal organs of fish taken from the lake or the rivers.

The Environment Department is testing the water to determine if the algae is a type that emits toxins and said results are expected within two weeks.