The incident occurred Oct. 22 at Fort Zumwalt East High School in St. Peters, Mo., the St. Louis Post-Dispatch reported. Officials said the students were on a bus returning from a football game that had been rained out.
Bernard DuBray, superintendent of the Fort Zumwalt School District, said some of the students recorded the masturbation on cellphones and posted the results on the Web. When they realized officials had learned of the incident, they deleted the recordings, he added.
"It's not anything we're proud of," DuBray said. "We have to have our coaches talk to the kids, and parents have to be aware, and we have to do a better job supervising. Nobody knew about it."