Students at Rosemount High School were held in classes Wednesday while police searched the building after bomb-making materials were found at a student’s home.

Nothing was found at the school.

The search occurred about 10 a.m., and students were kept in their third-period classes for about 15 minutes while police finished their investigation.

School and police officials described the search as “precautionary.”

Police decided to search the school after a parent found the “components for an incendiary device” in a student’s room on Flagstaff Court in Lakeville, according to Lakeville police. The home and those surrounding it were evacuated Wednesday while the Bloomington Bomb Squad removed the materials.

“There was nothing of any danger,” said Lakeville Police Chief Jeff Long. “There were materials that could be used to make an incendiary device, but not an actual device.”

The incident was still under investigation but no charges were anticipated, Long said.

Tony Taschner, Rosemount-Apple Valley-Eagan schools spokesman, said Rosemount High School officials contacted the student’s parent over concerns about the student’s conduct.

The parent then found the materials and called police.

Taschner said the initial call to parents was unrelated to what was found in the student’s room.

Police and administrators were talking with the student at the time of the high school search, Taschner said.

Rosemount Police Chief Mitch Scott said officers did a thorough search of the school.

“We were there for a while just making sure everything was safe and secure,” he said.

An email sent to Rosemount High School parents said the search was related to “alleged conduct by one of our students outside of school.”

A message also was sent to parents of Rosemount Middle School students. It described the incident and said students were kept inside the building until staff were notified that the “situation was resolved.”

Christopher Magan can be reached at 651-228-5557. Follow him at twitter.com/chris_magan.