Hi S.,
I agree with the responses about language barrier being a huge cause at this stage. My daughter is 2 1/2 and is still not speaking very much so when she gets frustrated/angry and begins to act out it's really the fact that she cannot communicate her frustration to us. If she's having a melt down I usually just leave her be and she gets over it very quickly. She'll typically just sit and cry for a bit. Of course if it seems like what she's doing could be dangerous I step in. During a melt down our children cannot think rationally so telling them "no hit" or "we do not throw" (which I have been guitly of too) means nothing to them and will not do a thing for them. Our kids get overwhelmed, overstimulated and we need to know when to just step back and let them figure it out. Sometimes that is the best thing for them. After my daughter has calmed down I hug and love on her and tell her that I love her.
I'm a firm believer in time out. I would suggest putting her somewhere else other than her room. You don't want to associate her room with bad behavior. Eventually that could lead into her not wanting to go near her room which of course creates even more issues. We use the bottom step of our staircase which is in a part of our house where I can see her easily and make sure she's staything there. There are no toys or anything to distract my daughter there either.
My sister gave me the Supernanny book for my birthday and it is wonderful!! It has so many great, practical tips. I would highly recommend it! Good luck with your daughter! Just be consistant and continue to show her how much you love her despite the lovely behavior our toddlers can have! :) God bless!!