The Royal Navy helicopter carrier HMS Illustrious has set sail from Portsmouth bound for the Mediterranean.

It is one of 10 ships taking part in the Cougar 13 deployment - which features ships departing from Portsmouth and Plymouth heading to the Mediterranean, and then on to the Gulf region to conduct military exercises.

The warship HMS Westminster is set to depart on Tuesday and is scheduled to dock in Gibraltar for a week as part of its voyage.

The exercise was pre-planned but comes at a time of increasing tensions between London and Madrid as the BBC's Duncan Kennedy explains.