City of Salem officials are warning residents about reports of people going door-to-door asking to test their tap water for cyanotoxins.

Salem spokesperson Kenny Larson said the city is not aware of any home-kits that can properly test for harmful toxins created by algae blooms in the North Santiam River system.

"We are using the fastest, most efficient technology," Larson said.

If anyone shows up asking to do a water test, Larson said residents do not have to open their doors and to call Salem Police Department's non-emergency line at 503-588-6123.

Related: Toxins in Salem's water back above advisory level