State police said Thursday that while hoax posts have circulated on social media saying there will be threats to schools Friday, the Connecticut Intelligence Center has been investigating and hasn't yet identified any credible or specific threats to schools in the state.

But superintendents in southeastern Connecticut have said there will be an increased police presence at schools Friday.

Rumors have been spreading on TikTok nationwide for at least several days and have made their way to other platforms, Connecticut State Police said in a news release. It's possible the threats originated from a TikTok challenge to skip school Friday.

"Any school threat that is made in Connecticut is immediately taken very seriously by law enforcement," state police said. "If a threat is determined to be a hoax, there will be a thorough investigation and arrests will be made. This could also lead to further consequences within the school district."

State police encourage parents to utilize monitoring apps like bark.us and download the apps their kids use.

The Connecticut Intelligence Center receives, gathers and shares information relating to criminal and terrorism threats with state and federal partners, including the state police, Department of Correction, Connecticut National Guard, FBI, Coast Guard, the U.S. Attorney's Office and U.S. Department of Homeland Security.

TikTok said in a statement Thursday, "We handle even rumored threats with utmost seriousness, which is why we're working with law enforcement to look into warnings about potential violence at schools even though we have not found evidence of such threats originating or spreading via TikTok."

Several school superintendents and police departments in southeastern Connecticut sent out letters about the threats, often using similar or identical language.

New London Superintendent Cynthia Ritchie and city police Chief Brian Wright said in a joint letter to families, staff and community members that the TikTok post refers to a threat to school safety "for every school in the USA, even elementary."

They asked anyone made aware of a potential threat to notify their school or police, or use the district's anonymous alerts system.

They noted the TikTok post appears to be part of a nationwide trend and didn't originate in their district, as did Groton Superintendent Susan Austin and East Lyme Superintendent Jeffrey Newton in their respective letters to parents.

"While we do not believe the threat to be credible, we are closely monitoring the situation and taking it seriously," Austin and Newton both wrote in their letters. They also both said, "This situation serves as a good example of why it is important to avoid sharing posts online that refer to school safety threats. Even if they are not credible threats, they can cause a great deal of stress and anxiety for our students, families, and staff."

Austin encouraged parents to notify a school staff member right away of any potential threat, and to talk to their kids about the potential consequences — such as suspension, expulsion or even legal consequences — of making threats online.

She said the district has been in contact with the Groton city and town police departments regarding the post, and out of an abundance of caution, there will be an increased police presence at each school Friday.

East Lyme police Chief Mike Finkelstein said the town also will be increasing the police presence at schools Friday. He described the viral nature of vague social media threats as problematic for local law enforcement agencies to track down because the origins could be anywhere.

"If you have a specific threat inside of the community, you know 'OK, this is focused here,'" he said. He noted police "have to take a look at each and every thing that may arise and determine: Is this a hoax or is this something that could turn into a realistic threat?"

Waterford Superintendent Thomas W. Giard III said he has been in communication with the town's interim police Chief Marc Balestracci, and while there is no evidence of a credible threat now, there will be an increased police presence at schools Friday.

"Reiterate to your child their responsibility to report this information to a trusted adult in the home or at school versus promoting and reposting these social media posts," Giard said. In Waterford, anonymous tips can be sent to speakup@waterfordschools.org or (860) 909-4004.

Norwich Free Academy Head of School Brian Kelly wrote in a letter to the school community Thursday, "We have no direct knowledge of any credible threats specifically to our school. Regardless, we will continue to be vigilant and monitor the situation, and we plan on opening school as normal tomorrow. In addition, we will maintain regular contact with our partners at Norwich Police Department should any credible threats emerge or any suspicious activity take place."

Kate Dias, president of the Connecticut Education Association teachers' union, said in a statement, "It's past time for candid conversations about the duty that social media platforms have in ensuring threats against schools are not allowed to go viral. Social media corporations have the ability to monitor, track, and remove posts that threaten public safety and must actively take steps to prevent their platforms from being used to promote violence in schools and communities."

Day Staff Writer Elizabeth Regan contributed to this report.

e.moser@theday.com