SEOUL: North Korea fired a short-range ballistic missile on Sunday, Seoul’s military said, the fourth show of force in a week as South Korea and the United States stage major military drills.

Seoul and Washington have ramped up defence cooperation in the face of growing military and nuclear threats from the North, which has conducted a series of increasingly provocative banned weapons tests in recent months.

South Korea and the United States are in the middle of 11 days of joint drills known as Freedom Shield, their largest in five years.

North Korea views all such exercises as rehearsals for invasion and has repeatedly warned it would take “overwhelming” action in response.

“Our military detected one short-range ballistic missile fired from around the Tongchang-ri area in North Pyongan province at 11:05 am (0205 GMT) towards the East Sea,” South Korea’s Joint Chiefs of Staff (JCS) said, referring to the body of water also known as the Sea of Japan.

The missile flew 800 kilometres (500 miles) and was under analysis by US and South Korean intelligence, the JCS said in a statement, calling the launch “a serious provocation” that violated UN sanctions.