North Korea fired several ballistic missiles toward the sea off its eastern coast on Saturday, according to South Korea's military.
South Korea's Joint Chiefs of Staff said it detected the launches from the coastal area of Wonsan at approximately 5:20 a.m. local time (20:20 GMT Friday). The missiles flew approximately 250 kilometres (155 miles).
South Korea said it boosted its surveillance posture and was closely exchanging information on the launches with the United States and Japan.
South Korea's presidential National Security Office convened an emergency security meeting with the Defence Ministry, the Joint Chiefs of Staff, and other relevant agencies following the launches.
The US Pacific Command said the launch event does not pose an immediate threat to US territory or to its allies, and reaffirmed Washington's commitment to the defence of South Korea and other allies in the region.
The missiles were launched one day after South Korea concluded five days of joint maritime drills with the United States and Japan focused on North Korea.
Hours after those exercises began on Monday, North Korea's Defence Minister Kim Song Gi criticised the drills and warned that Pyongyang was capable of taking "strong and reflective countermeasures from the standpoint of power."
Late last month, North Korea had condemned plans for the so-called Freedom Edge exercises in international waters off South Korea, describing them as a "threat" to Pyongyang and other countries in the region.
North Korea also fired a barrage of missiles into the sea on August 20, despite an overture from US President Donald Trump, who said he planned to meet North Korean leader Kim Jong Un this year.
That August launch came as South Korea and the United States held a scaled-back edition of their annual Ulchi Freedom Shield military exercises, following an order from Trump to reduce the drills. Trump had described the exercises as "inappropriate and hostile" toward North Korea, a move that alarmed US allies in the region.
Pyongyang has long condemned US-South Korea joint military exercises as rehearsals for invasion, and has frequently staged missile launches in response to such drills.
