Equity benchmark indices closed lower after a volatile trading session on Wednesday as investors weighed the impact of rising Covid-19 cases amid mixed global cues. Expanded lockdowns in certain states due to rising infections remained a concern for the market while the Prime Minister asked chief ministers to take decisive steps quickly to stop the emergence of second wave. At the closing bell, the BSE SandP Sensex was down by 562 points or 1.12 per cent at 49,802 while the Nifty 50 slipped by 189 points or 1.27 per cent to 14,721. All sectoral indices at the National Stock Exchange were in the negative terrain with Nifty PSU bank dipping by 3.7 per cent, realty by 2.9 per cent, auto and pharma by 1.8 per cent each. Among stocks, ONGC cracked by 4.8 per cent to close at Rs 109.50 per share while Bharat Petroleum Corporation was also down by 4.8 per cent to Rs 109.50 per share.