Arranging a group to go paintballing, do I need insurance?

Basically I'm arranging a group of people In my school to go paintballing in either Kerry or limerick. We will be meeting up at a certain place and I'll have a bus hired to take us there and back. We'll all be between 16 and 17 including me so my question is what liability do I have to any injuries and also will I need insurance should anyone get seriously injured.