Dubai, April 23 -- Iran fired on three ships in the Strait of Hormuz and seized two of them on Wednesday, intensifying its assault on shipping in the key waterway. The attacks came a day after US President Donald Trump extended a ceasefire while maintaining an American blockade of Iranian ports. The standoff between the US and Iran has effectively choked off nearly all exports through the strait - where 20% of the world's traded oil passes in peacetime - with no end in sight. Iranian media said the paramilitary Revolutionary Guard was bringing the two ships to Iran, marking a further escalation. The conflict has already sent gas prices skyrocketing far beyond the region and raised the cost of food and a wide array of other products. The pri...