<h3><br />''</h3>The US military said today that it had pronounced five missing Marines dead and was ending search operations nearly a week after two US military aircraft crashed off Japan.<br />''<br />''The accident was initially reported to have happened during a refuelling operation, but the military said, this had not been confirmed and that the circumstances were still under investigation.<br />''<br />''There are around 50,000 US troops stationed in Japan.<br />''<br />''<span style="color: #222222;"> </span><br />