FlightDeckDave - read this from BBC site...
"Matthew Masters, a passenger on the plane, said the pilot had announced about two hours into the flight that "there was a message that there may be a bomb on the plane".
Speaking to BBC News 24 from the terminal, Mr Masters said the reaction among passengers was "silence, a bit of uneasiness, just a bit of shock".
The pilot then told passengers that they would be landing within 15 minutes."
I'm not a professional pilot (yet) so can't comment on what procedures are in place, but I'd have thought it could have been worded a little more subtly...