The South Korean Joint Chiefs of Staff said that North Korea fired at least one ballistic missile toward the East Sea on Thursday.

The military authorities of South Korea and the United States are working on analyzing the details of the launch, including the range, speed and altitude.

The missile is presumed to be an intermediate or long-range missile as it reportedly went through stage separation.

The military is also looking into the possibility that the missile was an intercontinental ballistic missile.

The latest launch comes after the North fired more than 20 ballistic missiles and 100 artillery shells on Wednesday, taking issue with the large-scale Vigilant Storm air drills between South Korea and the U.S. running from Monday to Friday.