Halloween is approaching and a school district in Connecticut has called for a ban on clown costumes and any “symbols of terror” as the “creepy clown” phenomena has put Americans in multiple states on edge, the Associated Press (AP) reported Tuesday.

Authorities at New Haven Public Schools said Monday that principals and building leaders were urged to ban clown costumes until more information on clown-related incidents is available, according to the AP.

The development comes as investigators examine an Instagram account that posted four photos of the clowns. The photos were captioned warning several school areas to “watch out” and “wait and see.” Authorities are looking into whether the threats are authentic or fake.

School district officials said that there is no indication that the Instagram incident poses any real threat to students currently.

False reports or threats in connection to sightings of “creepy clowns” in the U.S. have reportedly led to the arrests of 12 people in at least 10 states. The trend of creepy clown sightings is also linked to at least one death, the report added.

First reports of the clowns sightings emerged mid-August in South Carolina. At the time it was claimed that the clowns lured children into the woods. Since then, people in Alabama, Georgia, Maryland, New Jersey, North Carolina and Pennsylvania, claimed to have spotted these clowns.