North Korea fired four short-range missiles over the sea off its eastern coast on Thursday, a media official at South Korea's Defence Ministry said, but provided no information as to the purpose of the firing.
North Korea fired the missiles at 5:42 p.m. local time (0842 GMT) from a mountain site just north of the border with South Korea, the official said.
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Launches by the North of short-range missiles are not uncommon as part of military exercises.
The firing came days after the beginning of annual U.S. and South Korean joint military exercises, which the North routinely denounces as a preparation for war.