South Korea's Joint Chiefs of Staff announced on Thursday morning that the launch of an "unknown ballistic missile" into the Sea of Japan had been detected.
According to Seoul, the missile was likely an intermediate-range or intercontinental-range ballistic missile, because a separation of rocket stages was detected.
An alert was sounded in Japan in the provinces of Miyagi, Yamgata, and Niigata, in north-central Honshu, for residents to seek shelter due to the launch. According to the Japanese government, the missile passed over Japan and landed in the Pacific Ocean. The missile's flight time was roughly 30 minutes.
About one hour after the first launch, Seoul reported a second missile had been fired. However, it seemed to be a shorter range weapon, splashing down in the Sea of Japan within moments of liftoff.
This would be the fourth time that the DPRK has fired a ballistic missile over Japan, but the first time one has flown over the main island of Honshu. The first two times were in 2017, and the third just last month; all flew over the northern island of Hokkaido.
The launch comes a day after the DPRK fired a barrage of 17 missiles and more than 100 rounds of artillery into the Sea of Japan - the most of any such bombardment.
Since the US and South Korea began major military drills in August, which rehearsed strikes on the DPRK, the socialist state has staged an unprecedented number of missile tests and artillery firing drills, including a variety of different weapons.
The DPRK has faced intense international pressure to give up its nuclear weapons and ballistic missiles, but it says it needs the weapons to guarantee its safety in the absence of a permanent peace treaty with the US and South Korea. The three nations have been in a state of war since 1950, with the fighting ending in 1953 with a ceasefire instead of a permanent peace treaty. The US maintains a garrison of 28,500 troops in South Korea.