A new trend is spooking communities in the US, with men dressed as 'creepy clowns' attacking people and causing security fears across several states.
Police and homeland security are investigating after scary instagram videos were posted in Philadelphia over the weekend.
The posts all use the word 'clown', and some even talk about blowing up schools in the area.
Earlier in Cincinnati, Ohio, a woman reported being attacked by a male dressed as a clown.
She claimed the man wore a red or orange striped clown suit, a mask, and a red wig.
The unusual reports started surfacing in August in South Carolina, when children told police that clowns had tried luring them into the woods by offering money.
The sightings of the 'creepy clowns' have increased over around the US the last few weeks.
On New York's Long Island, social media posts from anonymous clown accounts kept elementary children inside during recess.
Concerned parent Khalique Owens said: "Nobody knows how to defend against it because we don't know if it's a prank or if they'll harm people."
In Houston, Texas, an instagram video was posted showing clowns threatening to kidnap students or kill teachers.
Concerned parent Rochelle Hudson claimed: "This would make me drive my daughter to and from school and maybe walk inside to get her instead of her walking to the car by herself."
Now police are using social media to track down the costumed offenders.
In Lagrange, Georgia, police posted arrest warrants for four people on charges of making terrorist threats and disrupting schools, while police say they've arrested a dozen 'creepy clowns' for participating in menacing stunts or making false reports.
And the clown problem is far from a laughing matter, with police saying there is at least one deadly incident linked to a clown hoax.
In Reading, Pennsylvania, a 16-year-old was stabbed to death in a dispute. He was wearing a clown mask.
A 29-year-old now faces first degree murder charges.