A 16-year-old boy is in custody in connection to threats that led to the closure of several high schools Tuesday in two of Minnesota's largest school districts.

Police in Apple Valley said they heard about a social media threat Monday around 6:45 p.m. In response, Independent School District 196 — which covers Rosemount, Apple Valley, Eagan and parts of surrounding communities — said it closed five schools "out of an abundance of caution": Apple Valley High School, Eagan High School, Rosemount High School, Eastview High School, and the School of Environmental Studies, a magnet school for juniors and seniors.

Apple Valley police announced Tuesday afternoon a trace of social media posts led to a search warrant execution in neighboring Eagan, and the boy's arrest. Police say no weapons were found during the search.

"He has been taken into custody and will be transported to the Dakota County Juvenile Detention Center," police said.

Two high schools in District 191 — Burnsville High School and Burnsville Alternative High School — were also closed "as a precaution," district officials said. All other schools in the district continued as normal.

"We extend our sincere gratitude to our partner agencies and Independent School District 196 for their collaboration and support in helping restore safety and normalcy to our communities," Apple Valley police said.  

Parents tell WCCO they appreciate the districts taking the online threats seriously, but have questions about the timing. Kayla Woodworth woke up to an email from District 196 and was shocked that her son, who attends Highlands Middle School, wasn't also being sent home.

"I felt fear immediately. I was terrified for my child," Woodworth said. "And I felt frustration for the younger children. And why were they not being prioritized as well? Why was their safety not a concern?"

Police say they expect to submit formal criminal charges to the Dakota County Attorney's Office.