COLUMBUS, Ohio — A health warning for toxic algae at a Lake Erie beach in northwest Ohio has been strengthened after tests revealed high levels of a liver toxin in the water.

The Columbus Dispatch reports state officials have posted a stronger warning at Maumee Bay State Park's beach in Lucas County. The previous warning told people not to touch blue-green algae scum or swallow lake water, but it has been upgraded to recommend against swimming and wading.

Tests detected a liver toxin called microcystin in concentrations more than twice as high as a safety standard the World Health Organization set for swimmers.

The newspaper reports that researchers say toxic algae across the western basin of Lake Erie is the worst recorded there since tracking began in 2002.