ships said to be shown here are being held at the crimea port in kerch. ukraine says the ships were planning to enter the strategic waterway, the kerch strait before they were fired on. russia closed the strailt sunday but state media reports it s now been reopened for civilian vessels, and this dramatic video comes from ukraine s minister of internal affairs. it appears to show a russian ship ramming a ukrainian tugboat on sunday. ukraine s president is furious and says he wants parliament to declare marshal law. let s turn to cnn s ivan watson who is monitoring all of this from hong kong. he joins us now live. so, ivan, you are very familiar with this region and what s been happening between russia and ukraine. explain to us where this is going and the impact so far of these increased tensions. reporter: rosemary, ukraine and russia, two neighbors, former soviet states that have been at odds for years, but now for perhaps one of the first