Police in the US town of Greenville, South California, are investigating multiple reports of clowns lurking around which has left some residents scared.

Some of the clowns are said to be appear menacing and have allegedly offered children money to follow then, NBC News reports.

The local sheriff's office has boosted patrols around an apartment complex after a group of men opened fire into woods behind it after reportedly being spooked by "recent clown activity".

Property management at the Fleetwood Manor apartments have also circulated a flier asking residents to "ensure your children's safety keep them in the house during night hours".

According to a police report, multiple Fleetwood Manor residents, including children, saw the 'clowns' some of which allegedly carried flashing green laser lights.

Donna Arnold said her son was one of the children who saw one of the mysterious figures but at first she thought "he was telling a fib".

However, the next day, "30 kids ... come up to me and said, 'Ms. Donna, Ms. Donna, there's clowns in the woods, there's clowns in the woods.' My child was with me, so I knew they had to see something, " Ms Arnold said.

"There was more than one kid that seen them, so I feel confident that he was telling the truth."

A purported image of one of the clowns, which has not been verified, has been posted on Twitter by Greenville resident Kevin Thomas, with the caption: "Just spotted a major freak behind fleetwood apts."