North Korea fired two short-range missiles into the Sea of Japan on Monday, the third straight day of launches, South Korea's Defense Ministry said.
The second launch, made between 4 p.m. and 5 p.m., followed a launch shortly before noon, the ministry said.
Yonhap News Agency quoted a Defense Ministry official as saying the missile launched shortly before noon appeared to be a KN-02 short-range missile.
"We are closely watching the movements of the North's military in case of further launches," the unidentified official was quoted as saying.
North Korea has launched six short-range missiles in the past three days, including three Saturday and one Sunday.
Meanwhile, a top-ranking official of President Park Geun Hye's government urged North Korea on Monday to stop aggravating tensions on the Korean Peninsula with missile launches.
"Whether it's a test-firing or armed demonstration, North Korea should not engage in tension-creating acts," Kim Jang Soo, head of the national security office, was quoted as saying by presidential spokeswoman Kim Haing, according to Yonhap.
North Korea said via its official media that the launches were part of normal military exercises.