This photo provided by the North Korean government purports to show a missile test at an undisclosed location in North Korea, as taken sometime between Sept. 25 and Oct. 9. AP

North Korea fired one short-range ballistic missile (SRBM) into the East Sea on Thursday, its second missile provocation in a little over a week, according to the South Korean military.

The Joint Chiefs of Staff (JCS) said it detected the launch from the Wonsan area in Kangwon Province at 10:48 a.m., and that the missile flew some 240 kilometers at an apogee of around 45 km at a top speed of Mach 4.

Shortly before the launch, the South and the U.S. staged a "preplanned" missile defense exercise involving the allies' Aegis-equipped destroyers, the JCS said.