11 yr old boy eye damaged while playing in school who is liable?

My 11 year son playing the game with his friend in school during the playing through wood stick and the stick touch the eyes of his friend and damage the eyes of his friend, parents of injurious boys report to police and demanded compensation and police demanded the money 1. Can be file civil case ? 2. Can be action by police ? 3. Can i liable of injurious during school playground 4. Can be safe from police torcher 5. Can be liable school?