The Spanish Guarda Civil boat was said to have sailed across an American sub in the shocking incident. Warning flares were reportedly fired by the British Navy boat to warn off the European vessel. It comes as tensions heighten around the UK-controlled peninsula after a series of aggressive acts by Spain. A source said: “This is not only a very dangerous game for the Spanish to play but it is unbecoming of a NATO ally to treat the US Navy with such contempt.

“The US Navy guarantees the security of the Med Sea for all of NATO and ought to be able to damn well visit any port it wants whether its Gibraltar or not.” The incident was said to have happened last month as the American sub docked in Gibraltar. Another source said: “We are used to brinkmanship but this flies in the face of any rule book on maritime safety. “This is a nuclear powered submarine, and trying to disrupt its path is seriously dangerous.” READ MORE