Indian stock markets settled in the red on Thursday as escalating tensions in West Asia and again a sharp rise in crude oil prices weighed on investor sentiment. The frontline indices continued to fall. Sensex closed at 76,034.42 points, down 829.29 points or 1.08 per cent, while Nifty closed at 23,639.15 points, down 227.70 or 0.95 per cent.