A North Korean ballistic missile landed less than 60 kilometres off South Korea's coast on Wednesday in a barrage of apparent tests President Yoon Suk-yeol said was "effectively a territorial encroachment".
The launch of at least 10 missiles from Pyongyang's territory prompted South Korea to issue rare air raid warnings and launch missiles in protest.
The missile landed outside of South Korea's territorial waters, but south of the Northern Limit Line (NLL), a disputed inter-Korean maritime border.
South Korean warplanes fired three air-to-ground missiles into the sea north across the NLL in response, the South's military said.
An official said the weapons used included an AGM-84H/K SLAM-ER, a US-made "stand-off" precision attack weapon that can fly for up to 270 kilometres with a 360-kilogramme warhead.
The South's launches came after Yoon's office vowed a "swift and firm response" so North Korea "pays the price for provocation".
The North Korean weapon was one of three short-range ballistic missiles fired from the North Korean coastal area of Wonsan into the sea, South Korea's Joint Chiefs of Staff (JCS) said.
The JCS later said as many as 10 missiles of various types had been fired from North Korea's east and west coasts.
The JCS said at least one of the missiles landed 26km south of the NLL, 57 km from the South Korean city of Sokcho, on the east coast, and 167km from the island of Ulleung, where air raid warnings were issued.
"We heard the siren at around 8:55 am (0:55 am CEST) and all of us in the building went down to the evacuation place in the basement," an Ulleung county official told Reuters.
"We stayed there until we came upstairs at around 9:15 (1:15 CEST) after hearing that the projectile fell into the high seas."
A
Read more on euronews.com