Investors brace for a surge in oil prices, pressure on stocks and volatility across financial markets after the U.S. bombs Iran's nuclear sites.

The price of Brent crude oil, the international standard, rose 2.6% to $79 a barrel. U.S. crude rose 2.6% to $75.76 a barrel.

Stock indices across Australia, Japan, Korea, mainland China, Hong Kong and Korea fell up to 0.90 per cent. Gift Nifty was down 21 points or 0.08 per cent at 25,001.50, hinting at a muted start for the market.