"Our military detected two short-range ballistic missiles fired from around Junghwa area in North Hwanghae province from 07:47 am (2247 GMT) towards the East Sea," South Korea's Joint Chiefs of Staff (JCS) said early Monday, adding the two projectiles flew about 370 kilometers (230 miles).
According to Japanese media, quoting the country's Coast Guard, the projectiles most likely landed outside Japan's exclusive economic zone.
The launch is the latest in a series of weapons tests by the North. Pyongyang has been conducting a flurry of such tests in response to regular war games performed by the United States and South Korea, which the North sees as rehearsals for the invasion of its territory.
Seoul and Washington concluded their regular springtime exercises, called Freedom Shield 23, last week, but are now conducting amphibious landing drills involving a US amphibious assault ship.
On Friday, Pyongyang said the joint drills were a practice for "occupying" North Korea, whose leader has called for "stronger war deterrence," including "more developed, multi-faceted and offensive nuclear attack capability."
Also on Friday, North Korea said it had tested an underwater nuclear attack drone capable of inflicting substantial damage on enemy ports and vessels.
North Korean leader Kim Jong Un personally oversaw the test, the official Korean Central News Agency, KCNA, said at the time. According to the KCNA, the drone drill was staged "to alert the enemy to an actual nuclear crisis."
The weapon's mission was to "stealthily infiltrate into operational waters and make a super-scale radioactive tsunami...to destroy naval striker groups and major operational ports of the enemy," the media reports added.
Last year, the North declared itself an "irreversible" nuclear power and Kim recently called for an "exponential" increase in weapons production, including tactical nuclear weapons.
He also ordered the North Korean military this month to intensify drills to prepare for a "real war."
MNA/PR