Mumbai; Profit booking, along with caution ahead of key global and domestic events and negative international indices, plunged the Indian equity markets on Tuesday. Consequently, the key indices provisionally closed the day's trade deep in the red, as heavy selling was witnessed in automobile, healthcare and banking stocks. The wider 51-scrip Nifty of the National Stock Exchange (NSE) declined by 45 points or 0.52 per cent to 8,590.65 points. The barometer 30-scrip sensitive index (Sensex) of the BSE, which opened at 28,121.37 points, provisionally closed at 27,949.89 points (at 3.30 p.m.) -- down by 145.45 points or 0.52 per cent from the previous close at 28,095.34 points. The Sensex touched a high of 28,149.53 points and a low of 27,927.13 points during the intra-day trade. The BSE market breadth was tilted in favour of the bears -- with 1,642 declines and 1,056 advances. Both the key Indian indices had ended on a higher note during the previous trade session on Monday due to short covering, expectations of key reforms and healthy inflow of foreign funds. On Monday, the equity markets also touched their new closing highs in almost a year. On a closing basis, the NSE Nifty had touched a new 52-week high, whereas the BSE Sensex reached its highest closing levels in 11 months. The barometer index had gained by 292.10 points or 1.05 per cent to 28,095.34 points, while the NSE Nifty edged up by 94.45 points or 1.11 per cent to 8,635.65 points.