Method of attack on tankers remains key evidence against Iran

Release of colour images adds more clarity to debate but fails to prove responsibility

The sophistication of the attacks on two shipping tankers in the Gulf of Oman last week had already led most independent analysts to conclude Iran was responsible for the high-profile explosions.

But there has been scepticism from some key countries, including Germany and Japan, after the US initially released a grainy black and white video it said showed Iranian forces removing an unexploded mine from one of the two targeted ships. Iran has denied involvement.