Schools in central and southern Maine are expected to be on high alert Friday following a wave of threats posted to TikTok that warned of violence.

The TikTok videos claimed multiple school shootings will take place Friday.

Police said they did not believe the threats, most of which did not name specific schools, were credible. Still, many school officials in Maine and across the country said they were aware of the social media posts and were bolstering police presences at their schools.

TikTok is a social media application that allows users to create and share short videos.

Administrators from the Mt. Blue school district in Farmington, Wales-based Regional School Unit 4 and Auburn, Brunswick, Yarmouth and Cumberland schools addressed their concerns Thursday in letters to the school communities.

“It appears that individuals far away from Maine have started yet another inappropriate use of the social media platform known as TikTok and they have succeeded in creating the hysteria they clearly desire,” Yarmouth Superintendent Andrew Dolloff wrote. “We have been in touch with local law enforcement and they have agreed that, while no threats have been made toward Yarmouth’s schools, they are going to increase their visibility and presence around our facilities tomorrow.”

The Cumberland and Brunswick school districts also expected to have heightened police presences Friday, according to messages written by superintendents. Both districts said local police have said there were no credible threats to their schools.

“Please know that our schools are safe places. We have protocols in place and that we work closely with local law enforcement,” Brunswick Superintendent Phil Potenziano wrote. “This continuous and deliberate attention to safety has been and continues to be a central priority for Brunswick. However, I would remind all school community members to be vigilant and report anything out of the ordinary to the police or the schools.”

Mt. Blue Superintendent Christian Elkington addressed the TikTok concern in a message that mostly addressed an unrelated threat from the middle school earlier this week.

“I want to assure everyone that your RSU 9 administration takes threats to our students, staff, school and district with the utmost importance,” Elkington wrote. “Lastly, please know that our administrators and School Resource Officer will be working from a higher level of concern over the next several days to hopefully ease concerns by helping our students and staff feel more secure in our schools.”

RSU 4 Superintendent Andrew Carlton said he had notified local police of the concern and asked that officers be at district schools Friday. Auburn School Superintendent Cornelia Brown sent an alert Thursday night to school staff and local residents that threats were not directed at Auburn schools.

Shannon Moss, spokesperson for the state Department of Public Safety, said the Maine Information and Analysis Center, along with other fusion centers across the country, will continue to monitor online activity that might pose a threat. As of Thursday night, Moss said, there had been no credible threat made against any school in Maine.

The TikTok threats came two weeks after a school shooting in Michigan resulted in four student deaths. Maine schools have been on alert, with at least three districts canceling school over the past week.

Lewiston schools will be closed Friday due to an unrelated threat. While a social media threat from a student following an altercation at Lewiston Middle School was addressed by Lewiston police, school officials and city police decided to close all schools in the district as a precaution.

The Auburn police also investigated a threat made to Edward Little High School last night and early this morning. Police determined the threat was not credible, and the Auburn schools are open Friday.

Times Record Staff Writer C. Thacher Carter and Portland Press Herald Staff Writer Dennis Hoey contributed to this report.