can you tell us what ages your sons are?
that might make a difference in how to respond...
Just make consequences when they "hurt" others, per their age and appropriately for their age.
Emphasize that a family is a "TEAM" and that they ALL have to have each other's back... to take care of each other, to care for one another, to help not harm.
Then they need positive modeling.
Do not get into "who's fault" it is... if one is hitting another, just give everyone the SAME discipline... ie: take away the toys. Take away dessert. Take away a special activity. Take away TV privileges. Take away a favorite item or clothing. Create "tally" marks for each infraction they do toward "others" and likewise for each "good" thing they do for others- then maybe they get a prize or something. Take away games or gadgets they have. No discussing it or getting too wordy, just do it. Take away "allowance" (if they get any). Make them EARN "good behavior" coins. Put them in their room and they have to ALL stay there and mull over it. Some teacher's do this... one bad apple, and the WHOLE class suffers. Then that way, they all are less prone to misbehaving because if ONLY 1 does something "bad" ALL will have to "suffer."
But it HAS TO BE age appropriate, no matter what method you use. And never demoralize or demean them.
Tell them it is simply NOT ACCEPTABLE, in this house.
If they yell, then so be it. Don't get into that with them. Address the issues.
Teach them about telling the truth. Not blaming. Not lying. Tell them that if they continue, YOU will not believe them and they will ALL have a consequence. Teach them about TRUST.
So many tips.. but again, it has to be age appropriate.
Your sons "seem" older... and if so, it's best to get them on board now....you don't want them to turn into bullies or something, and always mistreat their sisters. They need to KNOW how to care about and love their younger siblings too... and themselves. THIS is a "lesson" they need as well.
And perhaps, restrict what they watch on tv and/or play with.
Kids need "boundaries"... and when they don't have any, they act up. They need structure too. And positive things to do with their energy and physicality.
Good luck,
Susan