Reports have detailed that the intelligence agencies of South Korea and the United States were analyzing the launches, which occurred around 4:00 a.m. local time (19:00 GMT on Friday), to determine the type of missiles and other details.
The latest launch came three days after Pyongyang launched two short-range ballistic missiles toward the Sea of Japan.
North Korea carried out its previous missile launch on July 12. The new-type Hwasong-18 intercontinental ballistic missile is believed to have flown over 1,000 kilometers (621 miles) at a maximum altitude of over 6,000 kilometers on a lofted trajectory.
On Friday, the South Korean Defense Ministry threatened Pyongyang with "the end of the North Korean regime" in the event of a nuclear attack against Seoul after the North said that the deployment of US nuclear assets in the region could be a sufficient reason to use nuclear arms.
On Thursday, North Korean Defense Minister Kang Sun Nam criticized the deployment of a US nuclear ballistic missile submarine in South Korea earlier in the week, saying that Pyongyang could potentially consider it a sufficient basis for the use of nuclear arms for self-defense.