3yo old hitting/hitting phase?

[Figster]

Just turned 3 ds is hitting at his cm she's on verge of cancelling out contract every day seemingly he has done something "aggressive" to another child doesn't care if they are older or smaller than him. It seems born out of frustration he swipes at us at home if told off or not allowed to do something and we tell him that it's naughty.

We are trying to tell him how serious this is that he needs to listen to cm, not touch heads or faces, definitely no hitting not sure if we can do anything else?

Most people I've spoken to say their lo also went through this, is it common? How do you try and stop it?

Just telling a 3 year old might not be enough. He needs to see some consequences. For example if you hurt someone else you will sit in the corner for 3 minutes. Or you will not get

Or do it the other way. "If you do not hurt anyone tomorrow you can have ice cream for pudding" (or whatever).

Our DS has been hitting, pinching scratching since 18mo so I really feel for you! but I'd say it's getting marginally better. Has now just 4 and not yet at school. When out of his routine he seems worse so annoyingly for us, holidays are tough and at Xmas he said he wanted to kill me (whilst taking swipes).
I bought a book called '10 Days to a less defiant child'. Worth the read. A calm approach works wonders.
It might seem dramatic but would you consider a different cm who might handle him differently?
Our CM is firm and calm. Apparently his behaviour is perfect there. But not with us at home...