New Delhi, Oct 25 : BSE Sensex plunged more than 600 points to breach the 64,000 points mark on Wednesday. Sensex is down 610 points at 63,961 points. Heavy selling in Sensex heavyweights with Infosys down 3 per cent, NTPC down 3 per cent, Bharti Airtel down 2 per cent. Vaishali Parekh, Vice President - Technical Research, Prabhudas Lilladher said the Nifty is currently precariously placed with the overall bias maintained with a very cautious approach and as said earlier, the breach below 19,500 zone was very crucial with the trend and sentiment turning negative and now with 19,200 zone positioned as the important and crucial support zone, a decisive breach below shall trigger for further intensified selling pressure. Technically, the next major support zone lies near 18,850 levels and 18,600 zones of the significant 200 period MA where one can expect some consolidation. So as of now, it's a wait and watch scenario and for the overall bias to improve, would need a decisive move past the 19,500 zone to establish some conviction and anticipate for further rise, Parekh said. The uncertainties associated with the Israel-Hamas conflict will continue to weigh on markets in the near-term, says V.K. Vijayakumar, Chief Investment Strategist at Geojit Financial Services. Positive news like decline in the US bond yields and weakening crude can help the market to revive but it may not sustain given the uncertainty surrounding the West Asian conflict. Investors may opt for a cautious approach to the market till some clarity emerges on the geopolitical situation, he said. /IANS