Revolutionary Guard troops said to have taken control of ship at gunpoint last month; US forces monitored seizure but didn't take action as vessel went into Iranian waters

State television claims US warships took over vessel and removed its cargo, Iranian military was able to regain control of the ship and drive Americans away

Testimony from Norwegian-owned Front Altair's staff will be important in determining who is blamed for attack, as US points to Tehran

As targeted Japan-linked vessels in Sea of Oman are evacuated amid US-Iran tensions, Khamenei rebuffs PM Abe's mediation attempts

Nature of incident in Middle East waters still unclear, with US and UK navies investigating; pro-Iran Lebanese news channel Al-Mayadeen says, without evidence, 2 tankers targeted