North Korea fired off a ballistic missile late Monday night.

The Joint Chiefs of Staff(JCS) said it detected an unidentified ballistic missile launched toward the East Sea.

The South Korean military is in the process of analyzing the details of the projectile.

The launch comes two days after the North Korea launched multiple cruise missiles toward the West Sea, and five days after firing two short-range ballistic missiles into the East Sea.

The provocations follow the arrival of a nuclear-capable U.S. submarine at a port on Jeju Island a few hours earlier.