INDIANAPOLIS (AP) — The parents of a central Indiana boy claim their son was subjected to "horrific sexual abuse" by three second-grade classmates at a school run by Ball State University.

The lawsuit filed last week alleges the students' teacher and officials at Burris Laboratory School in Muncie failed to act to halt the alleged abuse. It also contends the four 8-year-old boys had "unfettered access" to pornographic videos they downloaded on school computers and iPads.

Ball State spokesman Tony Proudfoot says the school will "vigorously defend these unwarranted allegations."

He says Ball State learned in December 2011 of alleged inappropriate behavior among four second-graders at the school. Proudfoot says the suit's allegations "bear no resemblance to the evidence" in the case.