Iranian state media has released images of crew members on a British-flagged tanker that was seized in the Gulf.
Video footage and a photo appear to show cooks preparing meals and crew members being briefed by an Iranian official onboard the Stena Impero.
A meeting of the British government's emergency Cobra committee has been held after Downing Street called the seizure "unacceptable and highly escalatory".
Frank Gardner is the BBC's security correspondent. He talks to Susie Ferguson.
