In Kidlington, Oxfordshire, a man dressed as a clown and carrying a baseball bat was reported to have chased a 10-year-old child through a park.
Gloucestershire Police said it had received six reports of "clowns" behaving suspiciously or carrying knives. In one instance a child was followed.
A cyclist in Eastbourne, Sussex, was left "shaken" after someone dressed as a clown jumped out from a bush brandishing what he believed was an offensive weapon.
And in Sudbury, Suffolk, a boy was chased by "several people dressed as clowns".
A contributor to the Spotted: Loughborough Facebook page said: "I was walking through Shelthorpe cemetery via the footpath next to the school. I was approached by what can only be described as a clown with an axe. I have never been so terrified in my life."
Thames Valley Police said clowns were "tying up resources which could impact on calls to other incidents"