The South Korean Joint Chiefs of Staff (JCS) announced on September 2 that it had detected North Korea launching a series of cruise missiles into the Yellow Sea at around 4 a.m. the same day (local time), according to Yonhap news agency.

The type of missile and its flight range are unknown as the South Korean military is analyzing it. In a statement, the JCS said it is strengthening surveillance and vigilance and maintaining a readiness posture in close cooperation with the United States.

South Korea and the United States only concluded the Ulchi Freedom Shield exercise on August 31. The 11-day exercise was condemned by North Korea as an invasion rehearsal.

As part of that exercise, the US sent at least one B-1B strategic bomber to join the South Korean aircraft.

In response, North Korea conducted a drill that included a territorial attack scenario and launched two short-range ballistic missiles into the eastern sea on the evening of August 30.

North Korea said the missile launch was a tactical nuclear strike drill, simulating a "scorched earth" attack targeting major command centers and airfields in the South.

In March, North Korea announced that it had launched strategic cruise missiles armed with experimental warheads simulating a nuclear warhead.

At that time, the country's media reported that two Hwasal-1 strategic cruise missiles and two Hwasal-2 missiles were launched from North Korea's South Hamgyong province, hitting targets at sea.