Investing & Trading Online from USA

#1
I am NRI living in USA. I want to invest and trade in India. I have savings A/C and Demat A/C with ICICI Bank. They have ICICIDirect but NRI from USA can not trade. I tried HDFC, IndiaBull, 5Paise, and looks like they all allow NRI from MiddleEast and Gulf region but not USA. Can some one help ??