SKOKIE, Ill. — A suburban Chicago high school has suspended varsity football activities amid an investigation into alleged hazing involving the team.

Niles North High School Principal James Edwards sent a letter to parents and guardians on Monday about the alleged hazing, which reportedly happened over the weekend. Edwards says the school in Skokie took “immediate action” and contacted the Skokie Police Department.

Details haven’t been released, but police are investigating.

Edwards says in a statement that school officials have “zero tolerance for hazing or even the threat of it.”

The school’s varsity football operations have been suspended until further notice.