Pyongyang: North Korea conducted a firepower strike drill involving 600-millimeter ultra-precision multiple rocket launchers, attended by leader Kim Jong-un, state media reported Sunday.

According to Yonhap News Agency, a long-range artillery sub-unit of the Korean People's Army in the western area carried out the drill. The exercise took place the previous day and included 12 "600 mm-caliber ultra-precision multiple rocket launchers and two artillery companies," as reported by the Korean Central News Agency (KCNA).

The drill seemed to be a response to South Korea's military detecting about 10 ballistic missiles launched toward the East Sea from Sunan, near Pyongyang. These missiles flew approximately 350 kilometers and were perceived as North Korea's reaction to the ongoing annual South Korea-U.S. military exercise.

Kim Jong-un emphasized that the weapon will "immediately be used for their second mission as a means of massive, destructive strike" if deterrents fail to prevent foreign forces from launching an armed provocation or invading North Korea. Kim's daughter, Ju-ae, was also present during the supervision of the exercise.