India, July 21 -- Benchmark indices Sensex and Nifty closed lower on Monday, dragged down by heavy selling in blue-chip bank stocks HDFC Bank and Axis Bank amid margin-related concerns and a flare-up in US-Iran tensions.

The 30-share BSE Sensex declined 442.93 points, or 0.57 per cent, to settle at 77,708.52. During the day, it tanked 783.16 points, or 1 per cent, to 77,368.29.

The 50-share NSE Nifty edged lower by 95.80 points, or 0.39 per cent, to end at 24,238.50. Among Sensex shares, Axis Bank was the biggest loser, dropping by 5.48 per cent after its quarterly results over the weekend. HDFC Bank declined by 5.12 per cent.

"HDFC Bank has disappointed, particularly on the NIM front," V K Vijayakumar, Chief Investment Strategist, Geo...