SAN MATEO, Calif. (KGO) -- Schools in Oakland, Antioch, San Ramon, Fairfield, Burlingame and San Mateo have all now all been mentioned in threatening social media posts, which state clowns will cause harm on campuses.
That's in addition to an incident in Concord Wednesday where a clown tried to kidnap a child.
RELATED: Concord mom fights off clown accused of attempting to kidnap girl
Parents on the Peninsula have heard about the creepy clowns. A San Mateo dad said he's pretty sure it's a prank, but he's still cautious.
"You never know. They got a lot of weirdos out here these days," said Sione Lemani.
The San Mateo Police Department says two San Mateo high schools have been named in social media posts that claim a creepy clown is coming to campus.
"We don't know what the purpose is for why they're doing what they're doing and what their intentions are," said San Mateo police Lt. Ryan Monaghan.
RELATED: Fear hits Antioch school after clown threat on Instagram
Police say there is no credible threat behind the post, but they're acting with an abundance of caution.
"What we did is we increased patrols of the two schools in particular that were named and of all of our schools," Monaghan said.
In Antioch, the threat was specific that a clown was going to shoot at Dallas Ranch Middle School.
"It was a video of our bathroom and they're like, I'm here. I actually got tagged in it with a couple other friends," said one student.
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"The Instagrams and Snapchats, there's no filter. That stuff can get out and spread like wildfire," said Dallas Ranch Middle School principal Ed Dacus.
Police in San Mateo say students should not respond to any posts or answer any messages involving clowns on social media, but they should tell someone if they see anyone who seems out of place on campus.
RELATED: Clown reportedly trying to lure kids into woods
In Concord, a mom says she had a close encounter with clown at a bus stop on Willow Pass Road. The woman says a man in a clown costume and blue wig tried to grab her one-year-old daughter.
"Mom thought that maybe he way trying to pull her daughter away and she reacted by kicking him in the suspect in the shin two times," said Concord police Corp. Chris Blakely.
Investigators are hoping nearby businesses have surveillance video of the incident.
Peninsula parents, schools on edge after creepy clown threats surface