Suspense surrounding the Bihar poll results took its toll on markets on Thursday as the benchmark BSE Sensex tracking a mixed closing in Asia plunged to over one-month low of 26,304.20 as sell-off intensified.
Even the NSE Nifty came under pressure and settled below the 8,000-mark.
Mood remained fragile because of uncertainty over Bihar Assembly election results and disappointing quarterly earnings by blue-chips.
Exit polls are due later in the day and results are salted for Sunday.
Also, investors refused to play ball as they digested US Fed Chair Janet Yellen's announcement on Wednesday that a December rate hike is very much on the table as the economy has performed well.
There was bad news from the rupee, which at 65.74 lost ground against the dollar on sustained capital outflows, which added to the fear factor.
The BSE Sensex after opening a shade higher quickly turned negative and finally settled the day lower 248.72 points, or 0.94 per cent, at 26,304.20 after selling pressure accelerated towards the fag end -- its weakest closing since October 1.
The gauge had lost 37.67 points in Wednesday's choppy session.
The 50-share NSE Nifty broke below the psychological 8,000-mark by tumbling 84.75 points, or 1.05 per cent, to close at 7,955.45 after shuttling between 8,031.20 and 7,944.10.
"Nifty remained volatile, in a bearish mood throughout the day's trading session. Market players remained glued to the developments in Bihar elections, which markets believe may be a catalyst to the investment mood of FPIs and FIIs in the near term," said Hiren Dhakan, Associate Fund manager, Bonanza Portfolio Ltd.
Vedanta Ltd was the biggest percentage loser as it plunged 4.66 per cent while Sun Pharma dived 4.28 per cent after its US-listed arm Taro Pharma reported disappointing earnings.
Tata Steel tumbled 4.33 per cent ahead of its quarterly earnings later in the day.
BHEL, Bharti Airtel, GAIL, Cipla and Axis Bank too cut a sorry figure. As many as 23 Sensex stocks fell.
Coal India, NTPC, Hero MotoCorp, ITC, M&M and Maruti Suzuki scooped up gains though.
According to provisional data, FPIs bought shares worth Rs 33.16 crore on Wednesday.
Sector-wise, BSE realty index fell the most by dropping 2.63 per cent, followed by healthcare, banking, technology and IT.
In line with the overall trend, small-cap and mid-cap indices also ended in the red with losses of up to 1.59 per cent.