KALAMAZOO, Mich. (WOOD) — A post circulating on social media warning about people giving out face masks that will knock you out is false, Kalamazoo officials say.

A post seen on social media claims people are going door to door giving out COVID-19 masks. The post claims chemicals on the masks will knock homeowners out so that the people can then rob them.

In a Facebook post Monday, the Kalamazoo County Sheriff’s Office said it has investigated the claim, and contacted police agencies across the country.

“Not one case has been verified and no one has been able to find the source of the original posting,” the sheriff’s office wrote on Facebook. “Right now, law enforcement believes this is to be untrue and that an unknown source is intentionally scaring the public.”

The sheriff’s office asked people to stop circulating those types of social media posts unless it is coming from a law enforcement agency, and gave a reminder to contact law enforcement about any suspicious incident or person.

“KCSO and law enforcement around our nation take scare tactics and threats like these very seriously and we will always investigate and warn the public on any known actual threats to their safety,” the Facebook post said.