Police on Friday continued to investigate a number of threats against the Fridley School District, and authorities have identified a second person connected with them.

On Friday, Fridley police said a 10-year-old girl was a "person of interest" related to additional threats against the north metro school district.

On Wednesday, police arrested a 13-year-old boy in connection with a threat posted on Snapchat, which led school officials to call off classes. The nature of the threat has not been disclosed.

"Fridley Public Safety will be working with the Anoka County Attorney's Office to pursue charges on both juveniles," said Fridley police Lt. Kevin Titus.

While classes did not resume Friday as it was a scheduled day off for students, activities and athletics, community education classes and rentals will be held Friday through Monday. Tiger Club, the district's child care program for prekindergarten through sixth grade, also will be open, the district said in an update.

"We will have additional security measures in place as well as police presence throughout our events and activities tomorrow and Saturday," the district's statement said.

With Monday a scheduled day off for the Martin Luther King Jr. holiday, school is set to resume Tuesday, the district said.

The 13-year-old boy was taken to the East Central Regional Juvenile Center in Lino Lakes after his arrest.

The investigation including local, state and federal authorities is continuing, Titus said.

The school closures affected about 2,900 students who attend Fridley schools.