GREEN BAY, Wis. (AP) -

Green Bay police say a 13-year-old is suspected of making a social media post with a clown photo threatening schools in Brown County.

Police say officers are interviewing the teenager to understand motive and intent. But police say the threat was a hoax, and charges will be referred to juvenile authorities.

WLUK-TV reports police stepped up their presence outside several schools Monday morning.

The post was shared more than 400 times Sunday. Police say they found no specific threat, but precautions were being taken "to ensure the safety of students, staff and families."

The incident came amid a rash of hoaxes and threats of scary clown sightings across the country.