South Korea has threatened to "exterminate" North Korea's leadership and dropped bombs near the border after dictator Kim Jong-un fired a ballistic missile over Japan.
North Korea sparked fresh fears of military conflict after the missile flew over the island of Hokkaido before crashing into the sea.
The launch was one of the most provocative ever from Pyongyang and has sparked a rare response from Seoul, which showed off its might and issued a grave warning.
South Korean fighter jets dropped eight bombs in a simulated air raid and the defence ministry took the rare step of releasing footage of its own ballistic missile test.
A top official warned there would be catastrophic consequences if South Koreans are threatened.