Indices witnessed strong profit booking session led by index heavyweight stocks because of MSCI adjustment factor. Nifty cracked 186 points to close 1 per cent lower at 18,069 level. S&P BSE Sensex dropped more than 700 points and closed at 61,054 level. Nifty Midcap 100 and Nifty Small cap 100 also traded weak for the day to close around 0.70 per cent and 0.82 per cent lower respectively.