South Korea conducted a large-scale live fire exercise Monday on the East Sea, where North Korea has been upping tensions with a series of missile and rocket launches supervised by leader Kim Jong-un.
The drill involving K-9 self-propelled artillery units and 130mm multiple rocket launchers was held in the coastal county of Goseong, which borders the North.
The aim of the exercise was to role play "the scenario of a possible North Korean maritime provocation", South Korean Defence Ministry spokesman Moon Sang-gyun told reporters.
It comes during an extended period of elevated military tensions on the Korean peninsula, triggered by Pyongyang's fourth nuclear test on January 6.
Over the past month, Kim Jong-un has personally monitored numerous rocket and missile launches into the East Sea, including the North's first test of a medium-range ballistic missile for two years.
Late last month, Kim watched what state media called the country's largest-ever long-range artillery drill, involving multiple batteries of heavy-calibre units pounding an offshore island from a beach about 120 kilometres (75 miles) North of Goseong.
The muscle-flexing was largely a response to ongoing, large-scale military war games that South Korea and the United States hold every year -- much to Pyongyang's fury.
Monday's South Korean drill was focused on "mastering more efficient and accurate firing procedures at sea against enemy targets", the defence ministry spokesman said.
The North's fourth nuclear test in January saw the UN Security Council -- backed by Pyongyang's main ally China -- impose its harshest sanctions to date over the North's nuclear weapons programme.
The North responded defiantly, claiming a series of key breakthroughs in its development of a long-range nuclear strike capability, and threatening Seoul and Washington with nuclear attack.