However, if they are having difficulty, separating and trying again another day might be the best answer. The space and toys available will determine the kind of play to expect. An arsenal of war toys will lend itself to running and shooting and loud sounds and words. A puzzle will be quieter and more cooperative in nature. Large, open spaces invite fast movement while small, full spaces demand that people go slow.
Children feel good about being noticed for positive reasons.
The behaviors we pay attention to are the ones that often get repeated. Introduce a new game or snack time. Perhaps you could sit down together and review the rule that people are not for hurting. Next, talk about a different way the children might play to ensure nobody gets hurt. If this type of statement makes you uncomfortable, help the child restate what he has said without making an issue of it.