OWATONNA, Minn. — Owatonna High School went into lockdown Monday during an incident spurred by "offensive" social media comments, according to the district superintendent.

Owatonna Public Schools Superintendent Jeff Elstad told KARE 11 that the lockdown started at about 12:30 p.m. on Monday.

Owatonna police say officers responded to a "reported fight" at about 11:45 a.m. When they arrived they found "a large group of students shouting and being disruptive in the commons area and gymnasium."

One officer from another agency was assaulted by a juvenile, who was taken into custody, police said. Another juvenile was arrested for obstructing legal process, and a third was cited for trespassing.

No students were hurt and there were no physical altercations between students that police are aware of.

Police say that initial reports indicate some white students posted "racist comments on social media directed towards our black students." Police also say that there were social media posts about weapons being involved, but that is not correct.

"Over the weekend students made offensive comments using social media and unfortunately that carried into the school day today," Elstad wrote in an email.

Elstad said the district started investigating Sunday when they were made aware of the posts and "are working to resolve this issue."

"The safety of our students and staff remains our priority," he said.