Missile drills on board Royal Navy's nuclear submarine

The nuclear attack submarine HMS Triumph has returned home to Plymouth after patrolling the straits east of Suez.

Our defence correspondent Jonathan Beale has spent the last four days living on board the submarine for its final leg from Gibraltar back to the UK.

Here, he observes as the crew of HMS Triumph carry out firing drills for her Tomohawk cruise missiles - the same weapons that were used in Libya - and her Spearfish torpedo.