South Korean military on Wednesday claimed that North Korea fired several cruise missiles toward the Yellow Sea, local media said.
In a statement, the Joint Chiefs of Staff said that Pyongyang tested its missile early morning, Seoul-based Yonhap News reported.
"While strengthening our monitoring and vigilance, our military has been closely coordinating with the United States to monitor additional signs of North Korea's provocations," it said.
North Korea last week said that they tested an underwater nuclear weapons system in response to joint military drills conducted by the US, South Korea, and Japan.
Earlier, Pyongyang also tested a solid-fuel intermediate-range ballistic missile carrying a hypersonic warhead into the East Sea, in its first missile launch this year.