I remember this movie I saw on TV in the mid 2000s. I think the channel was HBO Family, but I could be wrong about that.
It was about these two groups of kids (I think they were in summer vacations) and they had these camps or something like it. One camp would pretend to be soldiers and the other were native americans (I think) and they would have this sort of prank war with some rules between them but then the kid who was the leader of the soldier camp decided not to follow the rules anymore and things got out of hand.
Also I think there was this Romeo and Juliet type subplot between a boy from the native american camp and the sister of the leader (or one of the leaders) of the soldier camp.
The specific scene I remember is one in which a boy from the native american camp was captured by the soldier camp and they threatened to put leeches on him so the boy would tell them some information abut the rest of the group.
The movie also referenced some sort of conflict between the parents but I do not remember much about that.