Mumbai, June 18 -- Indian stock markets opened under pressure on Wednesday as geopolitical tensions between Israel and Iran entered the sixth day, with the possibility of direct U.S. involvement adding to investor worries.

The Nifty 50 opened at 24,797.15, down by 65.05 points or 0.26 per cent, while the BSE Sensex fell 269 points to start the day at 81,313.9, a decline of 0.33 per cent.

Geopolitical tensions escalated further after U.S. President Donald Trump called for an "unconditional surrender" by the Iranian regime, something Iran has ruled out. Israel, which has reportedly achieved many of its military objectives quickly, is said to control the skies over Iran.

However, Iran's missile arsenal continues to pose a threat, and the ...