A student came forward in the afternoon to let staff know about another student possibly having a BB gun inside the school at 2222 E. Washington Ave., Kearney said in an email to parents. East's school resource officer was contacted, and the BB gun was found in the student's backpack within a few minutes, Kearney said.

The incident follows the arrest of two 13-year-old boys last week after Madison police say one of the boys was shooting a BB gun out of a school bus window, hitting two girls, and the other boy brought the BB gun inside Jefferson Middle School the following day.

"I want you to know that we take this situation very seriously," Kearney said. "I recognize that an incident like this can cause anxiety for families and students.

He said Madison police and the district's legal services department are participating in the investigation of the East High School incident.

For high school students, bringing a BB gun onto school grounds results in a five-day, out-of-school suspension and a recommendation for expulsion under the district's disciplinary policy.