The test was meant to "verify the combat application efficiency of the overall weapon system", the KCNA news agency reported.
The missiles flew about 125 miles, South Korea said, and fired from tracked launchers with forest camouflage.
The test may have been meant to send a threatening message to the United States, which has two carrier strike groups in the waters between the Korean peninsula and Japan, with a third carrier group now being sent to the region.
The missile test was North Korea's fourth in the span of a month, and comes after the United Nations Security Council imposed new sanctions on Kim's government last week.
Under UN resolutions North Korea is barred from using nuclear and ballistic missile technology.
Pyongyang launched several land-to-sea missiles early Thursday, under the supervision of leader Kim Jong Un, KCNA said. This is the site where earlier this week USA aircraft carriers USS Carl Vinson and USS Ronald Reagan completed joint exercises with the South Korean navy.
North Korea claimed it is closer to testing an intercontinental ballistic missile that could potentially hit any target in the continental United States.
After the successful test of the Hwasong-12 IRBM, possibly the technological predecessor to, if not a stage of, an eventual liquid-fueled North Korean ICBM, the South Korean defense minister declared that the North's missile program is progressing much faster than initially expected. On Monday, North Korea rejected a Seoul civic right group's offer to provide anti-malaria supplies.
A joint investigation by South Korean and USA militaries has concluded the craft were on reconnaissance missions for the North, which has denied sending spy drones, however, dismissing the findings as a fabrication.
The Joint Chiefs of Staff said a thorough investigation will be made of the object found south of the Demilitarized Zone that bisects the Koreas.
"The drone found this time looks sloppy but slightly more slender than previous ones", a South Korean military official told Reuters on condition of anonymity, because he was not authorised to speak to the media.
Last year, South Korea fired warning shots at a suspected North Korean drone, forcing it to turn back.
In what will likely become another source of animosities, Moon's government said Thursday that it will let two of the four North Korean fishermen recently rescued at sea resettle in the South in accordance with their wishes.
South Korea announced Wednesday that it would delay the installation of the remaining components of the Terminal High Altitude Area Defense (THAAD) system while it was assessing the system's environmental impact.