North Korea fired two projectiles believed to be ballistic missiles towards the waters off its eastern coast on Monday morning, authorities in both Japan and South Korea reported.

"North Korea has launched a suspected ballistic missile," the office of Japanese Prime Minister Fumio Kishida wrote on Twitter, later sharing Kishida's first tasks for officials, such as rapidly providing the public with analysis, protecting core assets, and taking "all possible measures for precaution."

South Korea's military later said it had tracked two projectiles.

Details on the test

The missiles were fired from North Hwanghae province shortly before 8 a.m. local time (2200 GMT/UTC on Sunday) and flew about 370 kilometers (roughly 230 miles), South Korea's Joint Chiefs of Staff said.

Both appeared to have landed in the sea outside Japan's exclusive economic zone, according to the Japanese government.

South Korea's military said it "strongly condemned" the launches, and would "maintain firm readiness posture" as it monitored North Korean activities.

It also said it would continue military activities with the US as planned.

The Japanese government also lodged a "strong protest" with North Korea, saying its missile launches threaten the safety and peace of Japan, the region and the international community.

UN resolutions prohibit North Korea from testing ballistic missiles of any range capability, but Pyongyang frequently flouts these. Some ballistic missiles can also be equipped with a nuclear warhead.

Flurry of activity amid US-South Korean drills

North Korea has launched more than 20 ballistic and cruise missiles across 11 launch events this year, as it tries to force the US to accept its nuclear status and seeks to negotiate sanctions relief.

North Korea has also increased its military testing intensity in the past couple weeks amid military drills by the US and South Korea from March 13-23.

North Korea claims the drills are a rehearsal for invasion, which Seoul and Washington reject.

Pyongyang also said that dictator Kim Jong Un had attended some of the week's tests.

Besides the string of missile tests, North Korean propaganda was keen to tout what it said was a successful test run of an underwater, nuclear-capable exploding drone. It said it could be used to create localized tsunamis in attacks on ships or ports.

Observers met the specific technical claims published by state news agency KCNA on Friday with skepticism, however.