The latest launch comes as North Korean leader Kim Jong-un vowed to increase the production of nuclear warheads "exponentially" and build a more powerful intercontinental ballistic missile.
The missiles were launched from Chunghwa County in North Korea's North Hwanghae Province at around 8 am local time on Saturday, Yonhap said, citing the South Korean Joint Chiefs of Staff (JCS).
South Korea issued the warning messages, fired warning shots, and scrambled fighters, attack helicopters and other warplanes to remove them, while it remains unconfirmed whether the vehicles carry any weapons, the official said.
Ahead of a major political meeting to set policy for the new year, North Korea fired two suspected short-range ballistic missiles on Friday, according to the South Korean military.
The White House on Thursday (local time) accused a private Russian military company, the Wagner Group, of taking delivery of an arms shipment from North Korea to help bolster Russian forces in Ukraine, reported The Straits Times.
The spokesperson for the National Aerospace Development Administration (NADA) said that the test was conducted primarily for evaluating the capabilities of satellite photography and data transmission system and ground control system.
Japan responded with a "major shift" in defence policy amid mounting threats from China and North Korea with a special focus on free and open Indo-Pacific (FOIP).
North Korea fired over 130 Artillery rounds on Monday which fell into the sea off its east and west coast, Yonhap news agency reported citing the Joint Chiefs of Staff.
After reports emerged of Pyongyang conducting its 7th Nuclear test, the spotlight has fallen on China once again on whether the country would maintain friendly ties with the country under all circumstances as Beijing has earlier voiced opposition to the North Korea's missile launch.