North Korea fired seven short-range ground-to-air missiles into the sea Thursday, South Korean officials said.
The South's Joint Chiefs of staff released a short statement on Friday, saying the missiles were launched from North Korea's western coast late Thursday and landed in waters off the eastern coast.
The JCS believes that North Korean leader Kim Jong Un attended the test-firing, an official said on condition of anonymity.
Pyongyang routinely test-launches missiles, rockets and artillery to protest annual joint U.S.-South Korean military drills.
One of the drills, Key Resolve, wound up Friday, but the other, Foal Eagle, is set to continue until April 24.
Pyongyang has long demanded the U.S. and South Korea stop the annual military drills, which it has called "a dress rehearsal for a northward invasion." Seoul and Washington insist they are deterrent in nature.
Earlier this month, North Korea's foreign minister said the U.S.-South Korean military drills are "unprecedentedly provocative" and could set off a war on the Korean peninsula.
Ri Su Yong also appeared to repeat Pyongyang's threat of a pre-emptive nuclear strike against Washington.
"The DPRK cannot but bolster its nuclear deterrent capability to cope with the ever-increasing nuclear threat of the U.S. Now the DPRK has the power of deferring the U.S. and conducting a preemptive strike, as well, if necessary," he said.