Sri Lankan sources say, after downing of ship armed with missiles, torpedoes; US military has said it aims to sink Iran's 'entire navy'

Sri Lanka's navy says around 140 people are feared missing after a military vessel went down off its southern coast.

The sinking of an Iranian naval ship off the coast of Sri Lanka can be seen in heart-stopping video – in which a torpedo fired by an American submarine triggers a massive explosion that took down the vessel.