On Thursday morning, North Korea fired an intermediate-range ballistic missile (IRBM) over Japan. This is the second such missile launch in just over two weeks, and as with the previous one, it flew over the island of Hokkaido and landed in the Pacific.

These IRBM test launches have lead to public warnings to seek shelter in parts of Japan, and have fueled fear about the possibility of a war. Today's launch went an estimated 800km further than the previous one, showing increasing range in their arsenal.

The IRBMs have a shorter range than North Korea's intercontinental ballistic missiles (ICBM), the kind that could hit the US mainland. The ICBMs have been less reliable, however, and there are considerable doubts about North Korea's ability to direct those missiles accurately.