In addition, the rupee depreciating against the dollar by 21 paise to 66.35 in early trade and surge in global crude prices hit the market mood.
The 30-share index slipped below the 26,000-mark by falling 190.25 points or 0.72 per cent to 25,970.65 as banking, metals, FMCG, oil&gas, PSU and IT sector indices were trading in negative territory, with losses up to 0.71 per cent.
Brokers said a weak trend in other Asian markets hit by growing tensions between Saudi Arabia and Iran and weak China data contributed to the fall.
Among other Asian markets, Japan's Nikkei plunged 2.59 per cent, while Hong Kong's Hang Seng was down by 1.22 per cent in early trade today. Shanghai Composite Index fell 3.94 per cent.