Royal Marines prepare for exercise

The UK is one of five countries taking part in the rehearsal

Five hundred Royal Marines have boarded the helicopter carrier HMS Ocean ready for a huge joint rehearsal of war at sea.

The servicemen from 42 Commando sail from Marchwood military port in Southampton on Thursday to join 5,400 other UK troops on exercise.

HMS Invincible is leading 20 Royal Navy ships to the east coast of America.

The Royal Navy say the exercise, called Rapid Alliance, is not linked to any deployment of more UK troops to Iraq.

France, Germany and the Netherlands are also taking part in Rapid Alliance, which starts on 1 June and lasts three weeks.

The Aurora deployment will provide us with an excellent opportunity to maintain our operational capability Captain Chris Clayton

The forces will meet in Norfolk, Virginia, at the end of the month ready for the rehearsal of full-scale warfare at sea.

Codenamed Aurora 04 by the Navy, the rehearsal will also be a trial for the UK's newest amphibious ship, HMS Albion.

Challenger tanks were among hundreds of armoured vehicles being loaded onto HMS Ocean as part of Thursday's preparations in Southampton.

HMS Ocean's commanding officer Captain Chris Clayton said the exercise would provide an excellent opportunity to "maintain our operational capability".

Navy spokesman Lieutenant Colonel Jani Marok said: "The 42 Commando are held at high readiness and if a contingent happened anywhere in the world, they can divert at the shortest possibility.

"This exercise has been planned for a long time, it's an important exercise for the Royal Navy.

"No decision has been made about further marines being sent to Iraq."