Two separate incidents happened on October 10 near 83rd and Mackinaw and another at 100th and Normal.
Police say they are not sure if these incidents are connected to a similar one earlier this month near Garfield Park.
Students coming in early for breakfast at New Sullivan Elementary School usually have some time to play before school, but not Wednesday Someone dressed as a clown was seen hiding near the playground Friday morning.
"They were running out the of the playground area on the north end of 84th to go find security and tell the school personnel," said Charles Bessett, parent.
"There's a group of kids came up to me and said, 'There's a clown around the building.' And I asked where he was located at. And they told me around the park. So I had notified security," said Theresa Moore, parent.
Sullivan's principal is working with Chicago Public Schools' office of safety and security. She's decided to keep kids inside as much as possible and when they go out, they go with security.
"It's sad. It's sad. It really is. And to prey on children at this time, right around the time where they want to go out and do trick-or-treating, it's unfortunate. But parents, I just encourage them to talk to their children," said Dr. Joyce Nelson, New Sullivan Elementary School.
The clown sighting happened after students at Ashe Elementary reported seeing a clown nearby at 83rd and Ingleside.
The principal at Fernwood Elementary says some of her students saw a clown nearby last week as well.
"When there is any type of suspicious activity around any Chicago public school, it's a concern with us. You know, and for a person to actually attempt to do anything near or on school grounds, it would not be tolerated," said Willie Sims, Chicago Public Schools.
At 101st and Normal, police say a clown tried to lure boys into his pick-up truck last Tuesday evening. Police have issued two community alerts regarding the clown near some South Side schools and some West Side schools.
"Anyone who's approaching a child trying to lure them to a place or lure them into their car, they should immediately run and try to find an adult and seek 911 or call police," said Monique Bond, Chicago Police Department.
