A spate of creepy clown sightings in South Carolina has perplexed police and worried parents, but their frightening appearance was no surprise to best-selling US horror author Stephen King.

King, whose 1986 novel "It" tells the story of a supernatural being that appears as a clown to terrorize the residents of a small Maine town, told the Bangor Daily News that fear of clowns touches a nerve with children and adults alike.

"Kids love clowns, but they also fear them; clowns with their white faces and red lips are so different and so grotesque compared to 'normal' people," the newspaper quoted King as saying in an article posted yesterday.

"The clown furor will pass, as these things do, but it will come back, because under the right circumstances, clowns really can be terrifying."

The clown sightings started around Greenville, South Carolina, last month when police began getting reports of clowns standing silently by roadsides, lurking near laundromats and trying to lure children into the woods with bags of cash and green laser lights.

Police in North Carolina have over the past week also reported a wave of sightings, suggesting a slow migration in the direction of the fictional town of Derry, Maine, where King's Pennywise carried out his rampage.

But police urged residents to remain calm after an adult man saw a clown emerge from the woods and chased the clown with a machete in Greensboro, North Carolina on Tuesday. A 911 dispatcher calmed the man down and the clown escaped unharmed, police said.

King's macabre imagination has produced dozens of shiver-inducing works including The Shining and Misery. In 2014 he was awarded the US National Medal for the Arts in recognition of his large oeuvre.

King admitted he'd be unnerved to find a pale-faced, red-lipped prankster skulking near his Bangor home.

"If I saw a clown lurking under a lonely bridge (or peering up at me from a sewer grate, with or without balloons), I'd be scared, too," he told the newspaper.