SYDNEY, Australia — “We’re coming back for you,” a post on Facebook warned. The purported threat? To send in the clowns.

If Australian news outlets and social media are to be believed, “20,000 anonymous clowns” are plotting a reign of terror.

The clowns — grown-ups in face paint and giant shoes — have threatened to do little beyond show up late at night in a handful of suburbs and look scary. However, the local news media has breathlessly described the group as “a chilling threat” and “creepy clown fanatics.”

The hysteria seems to have started with a Facebook page established last week. The anonymous creator of the page, called Clown Purge Australia, posted a photo of a clown, with a caption that read “IT” and an emoji of a red balloon, a homage to the blockbuster film that had its premiere in Australia last week.