U.S. and South Korean troops stage an amphibious landing operation as part of joint military manoeuvres.
The exercise took place on Thursday, about 360 kilometres south of the capital Seoul.
Around 13,000 U.S. sailors and Marines are taking part in the drill, along with over 2,000 South Korean military personnel.
Numerous vessels, as well as scores of amphibious armoured vehicles, fighter jets and helicopters have been mobilized for the training exerciese.
The two countries have been conducting the ongoing joint drill since early March.
Travis Brecher, Reuters