the hitting and fighting is getting out of hand

[AllOutOfNaiceHam]

My boys are 3 & 5. They are best friends, but lately their fighting has taken on another degree of aggression. Yesterday I walked into the room and found ds1 laying on top of ds2, his arm around him neck, trying to squish him because ds2 wasn't sharing a toy. I asked him to get off and let go of him, and he poked him in the eye and punched him in the back then ran off. Things like that happen several times a day at the moment, and we are at out wits' ends.
We've tried ignoring, talking about it, time outs, time ins, love bombing, rewards, taking stuff away.
He doesn't do it at school, but I have seen other children in his year punching each other in the playground.
He understands that hitting his brother hurts himband makes everyone sad, butbhe says that's why he does it, "because ds2 did/didn't do xyz and that made him sad." Explaining that that doesn't make it ok doesn't seem to help.

What else can I try?

Bump, anyone, please? :(

Read Sibling Rivalry by Faber and Mazlish (sp?)

Play with them together (board games, ball games) Don't tell one off in front of the other. Don't belittle one in front of the other. Praise them every time they play together in harmony, even if it is boisterous play.

There are lots of other things, but I cannot remember them sadly..Still working on brotherly love in this household and mine are 12 and 14. My nephews grew out of it at 14, and they are all best of friends with each other now, but it is definitely a stage that brothers seem to go through. Story of Joseph and Dreamcoat springs to mind

How do you not tell one off in front of the other if one is beating the crap out of the other or trying to wind him up?

subbing - my DSs are 3 and 5 too, though in our case it's usually the aggressive 3 year old roughing up his mild-mannered big brother. I have the Faber & MAzlish book on the way, love their How to Talk book so hoping for more insight...

You identify the problem rather than homing in on the perpetrator of the attack...aka...I see that ds2 is feeling very upset because he' s hurt and ds1 is feeling very upset because he wants that toy. Before the attack happens you try and establish ground rules (with help of the children's input) over how best to share toys. You work out what ds1 could do if he really wants the toy and ds2 is not giving it to him. Could he a) come and find you b) ask ds2 politely or c) arrange in advance that they will try and share it for a while. Ask their opinion, in advance (if the problem if regularily occurring) how to avoid the familiar row.
Also try and find out what triggers ds1's aggression..surely a combination of jealousy and frustration . Has he any toys he would like to keep to himself and not share with ds2 - could he empathise with how ds2 feels? Would it help if you joined in the game for a short while to make them feel the rules will be enforced? One of the helpful things is to empathise with how ds1 is feeling but to also make it clear that you will not tolerate violence as a reaction to the situation he finds himself, and you need him to find another solution to get ds2 to share.