US and South Korea stage military drill
31 March 2014 Last updated at 09:20 BST
The Navy and Marine Corps of South Korea and the US have carried out an amphibious landing drill as part of their annual joint military exercise.
It took place in Pohang on South Korea's coastline and is scheduled to run until 7 April.
Hours after the drill was staged, North and South Korea exchanged fire near a disputed border.