The Indian equity benchmarks extended losses in noon deals on the back of a broad-based selling pressure ahead of monthly expiry of March futures and option contracts. Rising Covid-19 cases across the country have sparked fears of fresh lockdowns which may impact the economic recovery, analysts said. The Sensex fell as much as 875 points and Nifty 50 index dropped below its important psychological level of 14,300. Selling pressure was so intense that all the 30 constituents in the Sensex and all the Nifty 50 stocks were trading with a negative bias.As of 12:32 pm, the Sensex was down 790 points at 48,390 and Nifty 50 index tumbled 229 points or 1.6 per cent to 14,319.India’s daily COVID-19 cases hit a five-month high on Thursday and the country put a temporary hold on all major exports of the AstraZeneca coronavirus shot made by the Serum Institute of India to meet domestic demand.”The market is definitely worried about the impact of the spread of COVID-19. There would be an economic impact and there are fears over a partial lockdown,” KK Mittal, an investment adviser at Venus India told news agency Reuters.The markets witnessed heightened volatility as futures and option contracts for the month of March were set to expire later in the day, analysts said.All the 11 sector gauges compiled by the National Stock Exchange were trading lower led by the Nifty PSU Bank index’s nearly 5 per cent fall. Nifty Bank, Auto, Media, Metal and Private Bank indexes also dropped between 2-3 per cent.Mid- and small-cap shares were also witnessing intense selling pressure as the Nifty Midcap 100 index crashed nearly 3 per cent and Nifty Smallcap 100 dropped 2.55 per cent.”Nifty can go down 14,200-14,220 levels but currently the market is oversold and can expect a bounce towards 14,380 during the latter half of the session. However, the overall scenario for market is looking weak,” Kshitij Purohit, head of international markets at CapitalVia Global told NDTV over phone.Indian Oil was top Nifty loser, the stock dropped nearly 4 per cent to 91. Bharti Airtel, State Bank of India, Coal India, Maruti Suzuki, Tata Motors, Eicher Motors, Axis Bank, NTCP, Bajaj Finance, UltraTech Cement, ITC, Adani Ports and Hindalco also dropped between 2.5-3.6 per cent.The overall market breadth was extremely negative as 2,243 stocks were advancing while 490 were advancing on the BSE.