Darling babies! Hard to believe such cuties can make such trouble.
Lorraine has lots of experience, and I second her expert advice.
I have brothers from different litters. Occasionally their wrestling gets out of hand. I raise my voice and bellow "nooo!" to make them stop and pay attention to me. This way I don't have to physically intervene and potentially get hurt. Sometimes I add clapping my hands or stomping on the floor.
Obedience and trick training helps. Any activity that fosters togetherness and constructive activity helps. When I have to break up the wrestling, I immediately make them perform a few tricks together like sit, down, shake hands.
Usually it is boredom and pent up energy that leads to the naughty moments. Sometimes there is a little jealousy over attention. As Lorraine wrote, try to pinpoint what sets off the attacks.