COEUR d'ALENE - High school softball players in North Idaho are being investigated amid allegations a teammate was stripped naked during a bus ride home from a game.

Kellogg School District Superintendent Sandra Pommerening said three teenage girls have been kicked off the softball team for bullying and harassing another student during the bus ride home earlier this month from a game in Potlatch. School officials learned about the incident through an anonymous note a day later.

The school district determined that the girls had been celebrating their win in Potlatch and tugging at each other's clothes on the ride home, Pommerening said.

"When kids forget to stop on teasing and playing around ... one student wound up being a victim in our opinion," she said.

The mother of the alleged 17-year-old victim in the case initially went to the Shoshone County Sheriff's Department and said the school notified her three days after the incident.

The complaint has since been forwarded to Kootenai County, where the case allegedly occurred.

Detectives started their investigation Wednesday, said Kootenai County Sheriff Lt. Stuart Miller.

He said the department is requesting charges of battery and possibly hazing against the three girls, who are 16 and 17 years old.

Miller said the incident occurred during the evening of May 3. While the bus was moving, the three girls allegedly held down the reported victim and took all her clothes off. No injuries were reported, he said.

There was a coach on the bus, he said.

Keith Greene, a fundraiser for the Kellogg School District athletics department, called the allegations "demoralizing."

"It's a horrible incident," he said.

The case is being investigated amid widespread efforts to crack down on bullying in schools.

Earlier this year, lawmakers worked to strengthen the state's anti-bullying law in the wake of a high-profile hazing case in eastern Idaho. Five former Blackfoot high school male athletes were charged involving alleged locker room bullying incidents.

The bill would have required school districts to provide training in bullying prevention for employees and adopt a series of consequences for students caught bullying, intimidating or harassing others. But the bipartisan measure failed to emerge from the 2011 session.