(CNN) As the coronavirus outbreak grows after killing hundreds in China, officials in several US states are cracking down on false information about the spread of the disease locally.

Most of the false information is originating online, spreading fear about the virus that has sickened thousands worldwide.

In Los Angeles County, public health officials warned residents Thursday that a letter claiming a potential coronavirus outbreak in Carson City is fake.

The letter purports to be from the LA County Department of Public Health and features the logos of the Centers for Disease Control and Prevention, the World Health Organization and Los Angeles County.

A letter purporting to be from Los Angeles County health officials is being distributed in Carson.

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