CAMBRIDGE (CBS) — An eighth-grade student from the Community Charter School of Cambridge was assaulted by classmates on a field trip to Washington D.C., the school told parents in an email Wednesday.

“The student is not physically injured, but the incident was quite serious. The assault took place in the middle of the night, while classmates and chaperones were sleeping,” school administrators wrote.

Cambridge police confirmed to WBZ-TV that a charter school had contacted them about a reported sexual assault. “We informed them that this would need to be reported to the agency where the crime occurred (Washington, DC area),” said police.

The school asked parents to help students refrain from spreading rumors and emphasized that “this is not who we want to be as a community.”

They also said counselors would be available to students.

Students involved will be disciplined but the school has not finalized those actions yet.