LAKE ELSINORE, Calif. (AP) — Southern California's Lake Elsinore has been closed to swimming, boating, kayaking and fishing due to an algae bloom that produces toxins that could be harmful to people and animals, officials said.

The city of Lake Elsinore issued a “danger” warning that exposure to toxic algae can cause rashes, eye irritation, allergic reactions or gastrointestinal problems. The toxins can be fatal to dogs.

Boiling or filtering will not make the water safe from Cyanobacteria, according to the warning posted last week.

“Until the water quality improves, additional sampling of the lake will take place and continue weekly,” the statement said.

Lake Elsinore has historically been vulnerable to algae blooms, but only began sampling for or learning about Cyanobacteria concerns in 2016, the city said.

The 3,000-acre (1,215-hectare) freshwater lake is a popular recreation area in Riverside County, about 70 miles (113 km) southeast of Los Angeles.