North Korea apparently has test launched several land-to-ship missiles, South Korea says.
Seoul's Joint Chiefs of Staff said several projectiles were fired early Thursday from the North's eastern coast town of Wosan. It gave no other details.
This would be the fourth North Korean missile test in a month, coming after the U.N. Security Council imposed more sanctions on Pyongyang last week.
The three most recent previous tests were of ballistic missiles.
North Korea appears to be determined to develop a missile capable of carrying nuclear weapons and able to reach the U.S. mainland.
The Trump administration has been leaning on China, North Korea's chief ally, to get it to rein in its nuclear ambitions.
Meanwhile, South Korea has said it will suspend any further deployment of a controversial U.S. missile defense system until an environmental impact assessment ordered by new President Moon Jae-In is finished.
Seoul agreed under Moon's ousted predecessor Park Geun-Hye last year to deploy the powerful missile intercept system to guard against threats from nuclear-armed North Korea, despite angry opposition from Beijing, which views it as a threat to its own military capabilities.
Two missile launchers have been deployed in the southern county of Seongju, where hundreds of residents have staged fierce protests over what they see as potential environmental hazards posed by the batteries used in the Terminal High Altitude Area Defense (THAAD) system.
There is "no need to withdraw" the two launchers that already have been deployed, a senior official at South Korea's presidential office said.