VANCOUVER, Wash. (KOIN) — A dangerous algae bloom at Vancouver Lake “intensified” over the weekend, Clark County Public Health said in a tweet.

Officials say they took new samples from the lake and will keep the public posted on the results by the end of the week.

“Toxins from harmful algae can make people sick and can be fatal to pets,” said Clark County Public Health.

Officials also encouraged the public to stay away from floating scum.